Complete General Science Notes | B.Ed (HONs) Part - I Semester - I

 

UNIT  NO - 01

• Science in personal and social perspectives:

Science, whether it's biology, physics, chemistry, or any other field, plays an important role in various aspects of our personal and social lives. From the way we understand the natural world to the innovations and technologies that shape our society, science influences our daily lives in significant ways. 

• Personal Perspective: 

From a personal perspective, science helps us make sense of the world around us and understand how things work. For example, through the field of biology, we can learn about our bodies, how they function, and how to take care of them. This knowledge can help us make informed decisions about our health and wellbeing. Further, science empowers us with critical thinking skills. It teaches us to be curious, ask questions, and seek evidence-based answers. By applying the scientific method, we can evaluate information and make informed decisions in our personal lives. We can research and analyze topics such as nutrition, climate change, or vaccination, allowing us to form evidence-based opinions. Science also sparks our curiosity and wonder about the world. Whether it's exploring at the vastness of the universe or conducting experiments in a laboratory.

• Social Perspective: 

From a social perspective, science plays a crucial role in shaping society and solving societal challenges. Scientific knowledge informs policy decisions, public health strategies, and sustainable development initiatives. For example, climate science helps us understand the impacts of human activities on the environment, informing discussions and actions to mitigate climate change.Science also drives innovation and technological advancements. From medical to communication technologies, science enables us to develop new technologies that improve our lives and transform industries. Think of advances in medicine, such as the development of vaccines or life-saving treatments, or breakthroughs in renewable energy technologies. Moreover, science fosters collaboration and international cooperation. Scientists from different countries work together to conduct research, share knowledge, and solve global challenges. This cross-border collaboration enables us to address issues like infectious diseases or environmental degradation on a global scale. 

1. Motorbike helps us to travel easily. 
2. To cook food 
3. Intake of food and nutrients 
4. To make us aware from illnesses 
5. To solve problems in our life 
6. Understand the nature 
7. Communication and Entertainment (Technology) 
8. Medicines 
9. Industries

• Scientific Search Method:

1) Observation: Information we get through our five senses about a physical phenomenon. 

                                                OR

The process of reaching a conclusion about something from evidences/observation. 

2) Inference/Hypothesis: A nation of scientist on which he tries to explain the phenomenon. 

3) Experiment: A scientific procedure under taken to a hypothesis. 

4) Theory: An elaborated explanation about the phenomenon on the basis of experiment/hypothesis. 

5) Law: A statement that describes an observable occurrence in nature that appears to always be true.

UNIT NO - 02

Populations and Ecosystem

• Basic needs of living things:

Living organisms have certain basic needs in order to survive and thrive. These needs can vary slightly depending on the specific organism, but some common basic needs include: 

1. Food: All living organisms need a source of energy to survive. This energy is obtained through the consumption of food, which provides nutrients and raw materials for growth and maintenance of bodily functions. Different organisms have different dietary requirements, such as plants using photosynthesis to produce energy from sunlight, while animals consume other organisms for food. 

2. Water: Water is essential for all living organisms. It is involved in numerous biological processes, such as maintaining temperature, transporting nutrients and waste, and facilitating chemical reactions within cells. Organisms need access to water to stay hydrated and to carry out these essential functions. 

3. Shelter: Living organisms need a suitable environment that provides protection and shelter. This could be a physical structure, such as a tree for a bird or a burrow for a rabbit, or it could be a specific habitat or ecosystem, such as a forest or a coral reef. 

4. Oxygen: Oxygen is required for cellular respiration, which is the process by which organisms convert food into energy. Many organisms, such as humans and animals, rely on oxygen in the air or water to breathe and carry out this vital process. 

5. Sleep: Many organisms require periods of rest and sleep in order to maintain optimal health and functioning. Sleep allows the body to repair and regenerate cells, consolidate memories, and conserve energy. 

• Reproduction: 

Reproduction is a fundamental biological process that allows organisms to continuation their species. It ensures the continuation of life and the passing on of genetic information to the next generation. These are just some of the basic needs of living organisms. Each organism is unique and may have additional specific needs depending on its physiology and ecological niche.

• Interdependencies of living things (symbiotic relationships) :

There are several different types of interdependencies or symbiotic relationships between living things. These include mutualism, commensalism, and parasitism. Mutualism is a symbiotic relationship where both organisms benefit from the interaction. An example of mutualism is the relationship between bees and flowers. Bees feed on the nectar of flowers, and in the process, they help to pollinate the flowers and enable them to reproduce. In return, the flowers provide the bees with a source of food. 

Commensalism is a symbiotic relationship where one organism benefits, and the other is neither harmed nor benefited. An example of commensalism is the relationship between cattle egrets and livestock. Cattle egrets feed on the insects that are stirred up by the livestock as they move through grassy areas. The egrets benefit by having a ready food source, while the livestock are neither harmed nor benefited by the presence of the egrets. 

Parasitism is a symbiotic relationship where one organism benefits, and the other is harmed. An example of parasitism is the relationship between ticks and mammals. Ticks feed on the blood of mammals, which harms the host animal. The tick benefits by obtaining a blood meal, while the mammal may experience irritation, disease transmission, or other negative effects as a result of the tick's feeding. 

These symbiotic relationships are found throughout nature and play a crucial role in the balance and functioning of ecosystems. Each organism's reliance on another for resources or services creates a network of interdependencies that contribute to the overall health and stability of the ecosystem.

• Ecosystems and Habitats:

Ecosystems: An ecosystem is a community of living things (such as plants, animals, and organisms) that interact with each other and with their environment. It can be as small as a backyard or as large as a forest, and it includes not just living things, but also the physical things they need to survive, like air, water, and soil. In an ecosystem, everything is connected and relies(depend) on each other to survive. 

Habitats: A place which provides organisms all requirements to survive. 

OR 

 A place where different kind of organisms live where the can find food, shelter, protection and mates for reproduction

• These are some types of Habitats: 

1. Forest Habitat: Forest habitats are areas covered with trees. They are home to a wide variety of plant and animal species, and provide shelter, food, and protection for many organisms. 

2. Desert Habitat: Desert habitats are arid and dry regions that receive very little rainfall. They can be sandy, rocky, or even icy, and are characterized by extreme temperature fluctuations. Desert habitats are home to specially adapted organisms that can survive in harsh conditions. 

3. Ocean Habitat: Ocean habitats are the largest and most diverse ecosystems on Earth. They consist of saline water bodies, such as seas and oceans, and are home to a wide range of marine plants and animals. 

4. Grassland Habitat: Grassland habitats are characterized by vast stretches of grasses and few trees. They can be found in both tropical and temperate regions and support a variety of grazers like bison and zebra. 

5. Mountain Habitat: Mountain habitats are found in highaltitude regions with steep slopes and low temperatures. They can be home to a range of plant and animal species, many of which are specially adapted to survive in extreme conditions. 

6. Freshwater Habitat: Freshwater habitats include rivers, lakes, ponds, and wetlands. They are home to a variety of plants and animals, such as fish, amphibians, and water birds. 

7. Arctic Habitat: Arctic habitats are found near the Earth's North Pole and are characterized by extremely cold temperatures. They are home to unique animal species like polar bears, arctic foxes, and walruses. 

8. Rainforest Habitat: Rainforest habitats are dense, lush areas with high levels of rainfall and humidity. They are home to an incredible diversity of plant and animal species, many of which are found nowhere else on Earth. 

• Population growth Survival and Extinction:

Population growth: Population growth refers to the increase in the number of people living in a particular area over a specific period of time. It occurs when the number of births exceeds the number of deaths, and can also be influenced by immigration and emigration. 

Survival: Survival of fittest “a natural process resulting in the evolution of organisms best adapted to the environment” OR Survival of the fittest means that organisms that are better adapted to their environment are best suited to survive and successfully reproduce.

UNIT NO - 03

DIVERSITY AND ADAPTATIONS

• Diversity of Living things: 

Diversity in living organisms refers to the vast range of different species and variations within those species that exist on our planet. It encompasses the variety of forms, functions, behaviors, and interactions among living organisms. Diversity is seen at all levels of organization in the biological world, from the genetic and molecular level to the ecosystem level. It includes the classification and categorization of organisms into different kingdoms, phyla, classes, orders, families, genera, and species. The immense diversity in living organisms is a result of evolution, adaptation, and natural selection. It is essential for ecological balance and the overall health and sustainability of our planet. 

                                                                        Or

Simply diversity in living organisms refers to the variation in the characteristics of life forms on Earth. This variation includes the diversity of genes, species, and ecosystems. Genetic diversity is the variation in DNA within a species. 

1. Based on their physical features and their habitat 
2. Numerous organisms are classified on the basis of similarities and dissimilarities.

• Systems of Classifications: 

There are five kingdoms of classification and they are divided on the basis of: 

1. Presence or Absence of Nucleus 
2. Unicellular or Multicellular 
3. Due to differ in their body design they are classified

• Units of Classification: 

Basic unit of classification is Species. 

1. Closely related species are group together into genus, 
2. Similar genus group together into families, 
3. Families into orders, 
4. Orders into classes 
5. Classes into Phylum/Division 
6. Phylum/Division into Kingdom

• Kingdoms of Classification:

1. Kingdom Monera/Prokaryotae: This kingdom includes bacteria and other prokaryotic organisms. They are single-celled and lack a true nucleus. Example: Unicellular bacteria, Cyanobacteria. 

2. Kingdom Protista: This kingdom includes single-celled eukaryotic organisms. They can be plant-like (algae), animal-like (protozoa), or fungi-like. Example: Euglena, paramecium etc. 

3. Kingdom Fungi: This kingdom includes multicellular eukaryotic organisms,Non-chlorophyllousthat obtain nutrients by decomposing organic matter. Example: mushrooms and yeasts. 

4. Kingdom Plantae: This kingdom includes multicellular eukaryotic organisms that are capable of photosynthesis. They have cell walls and are generally immobile. Example: Apple tree, Orange tree etc 

5. Kingdom Animalia: This kingdom includes multicellular eukaryotic organisms, Non-chlorophyllousthat are heterotrophic and have the ability to move. They lack cell walls. Example: Goat, sheep, camel etc. These classifications are based on the characteristics and cellular structure of organisms. They help scientists organize and categorize different species for better understanding and study.

• Adaptations for survival: 

Non-chlorophyllous organisms have evolved various adaptations for survival without the ability to perform photosynthesis. These adaptations include: 

1. Obtaining energy from other organisms: Non-chlorophyllous organisms may be heterotrophic, meaning they obtain their energy by consuming other organisms. This can be done through predation, scavenging, or parasitism. 

2. Utilizing other energy sources: Non-chlorophyllous organisms may rely on alternative energy sources, such as chemosynthesis or fermentation. Chemosynthesis involves using inorganic substances, such as hydrogen sulfide or methane, to produce energy. Fermentation is a process that converts organic compounds into energy without the need for oxygen. 

3. Symbiotic relationships: Some non-chlorophyllous organisms form symbiotic relationships with photosynthetic organisms. For example, certain fungi form mutualistic partnerships with plants, where they receive sugars and other nutrients from the plant in exchange for aiding in nutrient absorption. 

4. Evolution of specialized structures: Non-chlorophyllous organisms may have evolved specialized structures or adaptations to enhance their ability to obtain energy. For example, carnivorous plants have modified leaves that capture and digest insects, allowing them to obtain nutrients that are lacking in their environment. 

5. Adaptability to harsh conditions: Simple organisms are often able to survive in extreme environments that would be inhospitable to more complex organisms. 

For example, certain bacteria can survive in highly acidic or alkaline environments, as well as in extreme temperatures or pressures. These organisms have evolved specialized structures or biochemical processes that allow them to thrive in these conditions. Overall, non-chlorophyllous organisms have evolved a range of strategies to survive without the ability to perform photosynthesis. These adaptations allow them to obtain energy and nutrients from alternative sources, ensuring their survival in various environments. 

• Evolution and diversity: 

Evolution: Evolution is the process of change in all forms of life over generations. It refers to the changes in heritable characteristics of species over time, resulting in new species arising from common ancestors. Evolution occurs through natural selection, genetic mutation, and genetic drift. It is driven by various factors such as changes in the environment, competition for resources, and reproductive success. The theory of evolution, proposed by Charles Darwin in the 19th century, provides a scientific explanation for the diversity of life on Earth. 

Diversity: Diversity refers to the range of different species, genes, and ecosystems found in a specific area.

• Teaching “Diversity and Adaptations” at elementary grades:

Teaching diversity and adaptations at the elementary level can help students develop an understanding and appreciation for the variety of life on Earth. Here are a few ideas for teaching this topic: 

1. Start with a discussion: Begin by asking students what they think diversity means and how they see it in their own lives. Brainstorm examples of diversity in culture, language, appearance, and abilities. 

2. Explore biodiversity: Introduce the concept of biodiversity by discussing the different types of living organisms found in different habitats. Show pictures and videos of diverse habitats such as rainforests, coral reefs, and forests. Discuss the different plants and animals that are found in these habitats and their adaptations. 

3. Introduce the concept of adaptations: Explain adaptations as traits or characteristics that help organisms survive in their environment. Show examples of physical adaptations such as camouflage, beak shape, and body coverings. Discuss behavioral adaptations as well, such as migration, hibernation, and communication methods. 

4. Conduct a habitat study: Divide students into small groups and assign each group a different habitat to research. Have them create presentations or posters that showcase the diversity of plants and animals found in their assigned habitat. Encourage them to include examples of adaptations specific to that habitat. Note: You can write this answer on your own experiences or in your way of teaching

UNIT NO - 04

EARTH : THE BLUE PLANET

• Earth: an inhabitable planet: 

Earth is the third planet from the Sun in our solar system and is the only known planet to support life. It has a diverse environment with a mix of land, water, and atmosphere that makes it suitable for life to thrive. Earth is a rocky planet with a solid surface and a thin layer of gas called the atmosphere that protects it from harmful radiation and regulates temperature. It has abundant water in the form of oceans, lakes, and rivers, which is essential for the existence of life. The atmosphere also contains oxygen, which is crucial for most living organisms. Earth's position in the habitable zone, where temperatures are just right for liquid water to exist, is another factor that makes it suitable for life. The planet also has a stable climate and a protective magnetic field that shields it from solar wind and cosmic radiation. These factors combined make Earth a habitable planet and unique in our exploration of the universe.

• Weather, Seasons, Climate: 

Weather: Refers to short term change in atmosphere Or Weather refers to the state of the atmosphere at a specific time and place, including temperature, humidity, precipitation, wind speed and direction, and other atmospheric conditions.Weather can change from day to day or even within hours. Weather conditions play a crucial role in daily activities, agriculture, transportation, and various other aspects of human life. 

Season: Long term specific in duration three or four months. 

Climate: Describe to weather is like over a long period of time in specific area.

• Categorize the world by continents, biomes, vegetation zones, climate zone:

Categorize the world by continents: The world can be categorized into seven continents: Africa, Antarctica, Asia, Europe, North America, Australia/Oceania, and South America. These continents are large landmasses that are separated by bodies of water such as oceans and seas. Each continent has its own unique geography, climate, and diverse cultures and is home to a variety of countries and regions. 

Biomes: It is long religion community primary determine by climate. 

Biota: Total collection of plants and animals. 

Vegetation Zones: Vegetation zones, also known as biomes or ecological regions, refer to large geographic areas with similar plant life and vegetation patterns. These zones are defined by factors such as climate, temperature, rainfall, and soil type. Different vegetation zones support distinct types of plant communities and ecosystems. Examples of vegetation zones include rainforests, deserts, grasslands, tundra, temperate forests, and coniferous forests. Each zone has its own unique composition of plant species and adaptations to survive in its particular environmental conditions. 

Climate Zone: Climate zones refer to large geographic areas with similar weather patterns and climatic conditions. These zones are typically defined by factors such as temperature, precipitation, humidity, and air pressure. The classification of climate zones is often based on the Köppen climate classification system, which categorizes climates into different types, such as tropical, arid, temperate, and polar. Each climate zone has its own characteristics and influences the types of ecosystems, vegetation, and human activities found within it. Climate zones play a crucial role in influencing the distribution of plant and animal species, as well as in shaping local economies and cultures

• Introduction to maps; reading and creating simple data charts: 

Maps are visual representations of the Earth's surface or a specific area, showing various geographic features such as rivers, mountains, cities, and countries. They provide a spatial reference and help us understand the location and distribution of different elements. When reading a map, it's important to understand the symbols and legends used to represent different features. For example, a blue line may represent a river, while green areas may indicate forests or parks. Maps can also show political boundaries, transportation networks, and topographic features. Creating simple data charts involves organizing and presenting information in a visually organized manner. Common types of charts include bar graphs, pie charts, line graphs, and scatter plots. These charts help convey data trends, comparisons, and relationships, making it easier to interpret and analyze information. When creating data charts, it's important to determine what information you want to display and choose an appropriate chart type. You'll also need to label and title your chart, ensuring clarity and accuracy. Using color, labels, and scales effectively can make your chart more visually appealing and informative. Both maps and data charts are essential tools for understanding and communicating information effectively. They can be used in various fields, including geography, social sciences, business, and economics.

Constant changes on Earth: rock cycle: 

Rock Cycle: One type of rock change into another type of rock under certain condition in cyclic manner. OR The rock cycle is a continuous process by which rocks are formed, broken down, and reformed over time. It involves various geological processes such as weathering, erosion, deposition, compaction, and cementation. The rock cycle is driven by the Earth's internal heat and external forces like wind and water, and it helps to recycle and transform different types of rocks in the Earth's crust. 

Cycle: There are three main types of rocks in the rock cycle: igneous, sedimentary, and metamorphic rocks. 

1. Igneous rocks are formed from the solidification of molten rock material, either below the surface (intrusive igneous rocks) or on the surface (extrusive igneous rocks). Examples of igneous rocks include granite, basalt, and obsidian. 

2. Sedimentary rocks are formed through the processes of weathering, erosion, deposition, compaction, and cementation. These rocks are made up of sediments that have been compacted and cemented together over time. Examples of sedimentary rocks include sandstone, limestone, and shale. 

3. Metamorphic rocks are formed when pre-existing rocks are subjected to high temperature and pressure, causing them to recrystallize and change their physical and chemical properties. Examples of metamorphic rocks include marble, slate, and gneiss. 

• River: (Erosion/Sedimentation):

1. River Erosion: River erosion refers to the process by which a river or stream wears away the land or deposits sediment in its channel, increasing its depth and width over time. It is primarily caused by the force of flowing water, which can exert considerable pressure on the bed and banks of a river, leading to erosion and the transport of sediment downstream. This erosion can occur through various processes, including hydraulic action, abrasion, and solution, and can result in the formation of landforms such as river valleys, canyons, and waterfalls. River erosion can have both beneficial and detrimental effects, as it can create fertile floodplains and provide sediments to maintain coastal deltas, but it can also lead to the loss of agricultural land, damage to infrastructure, and changes in river morphology. 

2. River Sedimentation: River sedimentation refers to the process by which sediment, such as sand, silt, and clay, is deposited or settles at the bottom of a river. Sedimentation occurs when the velocity of water decreases, causing the sediment particles to settle out of the water column and accumulate on the riverbed. Several factors can contribute to river sedimentation including erosion of upstream areas, deforestation, agriculture, urbanization, and construction activities near the river. These activities can increase the amount of sediment carried by the river, leading to deposition and potentially causing problems such as reduced water flow, increased flooding risks, and degradation of water quality. In natural river systems, sedimentation plays an important role in maintaining the overall health and functioning of the ecosystem. Sediment deposition provides nutrients for vegetation and habitats for aquatic organisms. However, excessive sedimentation can disrupt these natural processes and have negative impacts on both the river ecosystem and human activities.

• Earthquakes and Volcanoes: 

Earthquakes: Shaking of Earth due to the sliding of tectonic plates. 

Volcanoes: A volcano is a landform that is created when hot molten rock(magma) and ash escapes from an opening in the Earths surface. The molten rock and ashe becomes solid as they cool and this make a volcano. 

                                                                         OR 

A volcano is a opening in the Earths surface that rock, ash, and gases escape from. (lava rock, fragments, hot vapours, gases) 

Molten rock: Its is a hot, viscous fluid that is found under the Earths surface. 

Disadvantages of Volcano: 

A volcano can also release dangerous gases and ash into the atmosphere, which can cause health problems and damage to property. (Sulphur dioxide, Hydrogen Sulphide in high concentration). 

UNIT NO - 05

FORCE AND MOTION

• Force and Motion: 

Force: Act or process of pulling and pushing. 

Motion: If a body changes its position as compared to its environment is called Motion. 

• Types of Motion: 

1. Translatory Motion: 

Translatory motion refers to the movement of an object in a straight line or along a fixed path OR All bodies moves from one place to another place and all parts of body covers same distance. 

Parts of Translatory Motion: 

a. Linear Motion: A body moves in one direction and its all parts of body covers same distance 

b. Circular Motion: A body moves in a circle is called circulatory motion. For example: Earth moves around sun in circular motion. 

c. Random Motion: A body moves doesn’t move in a particular direction is called Random motion. 

2. Rotatory Motion: Rotatory motion refers to the movement of an object in a circular or curved path around a fixed axis. 

3. Vibratory Motion: A body moves in front and back, up and down is known as Vibratory motion.

• Physical Quantities: 

Anything which can be measured. 

Fundamental physical quantities are the basic building blocks of all other physical quantities. They are the most basic measurements that cannot be broken down further. 

The international system of units (SI) defines seven fundamental physical quantities. 

1. Length: The SI unit of length is the meter (m). It is used to measure distance and size. 
2. Mass: The SI unit of mass is the kilogram (kg). It is used to measure the amount of matter in an object. 
3. Time: The SI unit of time is the second (s). It is used to measure the duration of events and the sequence of events. 
4. Electric Current: The SI unit of electric current is the ampere (A). It is used to measure the flow of electric charge. 
5. Temperature: The SI unit of temperature is the kelvin (K). It is used to measure the hotness or coldness of an object. 
6. Amount of Substance: The SI unit of amount of substance is the mole (mol). It is used to measure the quantity of atoms, molecules, or ions in a substance. 
7. Luminous Intensity: The SI unit of luminous intensity is the candela (cd). It is used to measure the intensity of light emitted by a source. 

• Derived Physical Quantities:

Derived Physical Quantities are quantities that are calculated or derived from other base physical quantities. These derived physical quantities express the relationship between the base physical quantities. Examples of derived physical quantities include: 

Velocity: Derived from the physical quantities of distance and time. It is defined as the rate of change of position with respect to time. 

Formula: Velocity (v) = Distance (d) / Time (t) 

Acceleration: Derived from the physical quantities of velocity and time. It is defined as the rate of change of velocity with respect to time. 

Formula: Acceleration (a) = Change in velocity (Δv) / Time (t) 

Force: Derived from the physical quantities of mass and acceleration. It is defined as the product of mass and acceleration. 

Formula: Force (F) = Mass (m) * Acceleration (a) 

Power: Derived from the physical quantities of work and time. It is defined as the rate at which work is done. 

Formula: Power (P) = Work (W) / Time (t) 

Pressure: Derived from the physical quantities of force and area. It is defined as the force exerted per unit area. 

Formula: Pressure (P) = Force (F) / Area (A) 

Energy: Derived from the physical quantities of force and distance. It is defined as the capacity to do work or generate heat. 

Formula: Energy (E) = Force (F) Distance (d) 

Density: Derived from the physical quantities of mass and volume. It is defined as the mass per unit volume. 

Formula: Density (ρ) = Mass (m) / Volume (V) 

These are just a few examples of derived physical quantities. There are many more derived quantities that express various relationships between different base physical quantities.

• Quantities: 

Scalar Quantities: Those quantities which can be measured through magnitude and unit only are known as Scalar Quantities. For Example: time, temperature ,speed, distance, mass, etc. 

Vector Quantities: Those quantities which can be measured through magnitude, direction and unit are known as vector quantities. For example: Force, displacement, acceleration, velocity, weight etc. 

• S.I Units: 

1. Mass (Kg) 
2. Length (meter) 
3. Time (second) 
4. Amount of substance (mol) 
5. Electric Current(A) (Ampere) 
6. Temperature(K) (Kelvin) 
7. Intensity of light(cd) (candela)

• Law of Motion 

First Law of Motion/Law of Inertia A body continues it’s state of rest or uniform motion in a straight line unless an external force acts on it. 

Second Law of Motion When a net force acts on a moving body it produces acceleration in the direction of force. The acceleration is directly proportional to the force and inversely proportional to the mass of body. 

Third Law of Motion To every action there is an equal an opposite. 

UNIT NO - 06

PROPERTIES OF MATTER

• Physical Properties of Matter 

1. Density: Mass per unit volume, number of molecules in unit area. 
2. Atom: The smallest particle of matter in which electron, proton, and neutron are its fundamental particles. 
3. Element: Any pure substance in which all the atoms are same. 
4. Molecule: Combination of two or more atoms which are joined. 
5. Compound: When two or more different atoms are joined together chemically they form compound. Mixture: The combination of two or more substance.

THE END