Definitions [10]
Define the term matter. What is it composed of?
- Matter is defined based on its physical and chemical structure. It occupies space and has mass, particularly as opposed to energy.
- Atoms and molecules are the building blocks of matter, consisting of positively charged protons, neutral neutrons, and negatively charged electrons, respectively.
Define the term matter.
The matter is defined as anything that has mass and takes up space. The matter is found in solid, liquid and gas.
Define the following term of Atom .
Atom — An atom is the smallest part of an element that takes place in a chemical reaction.
Define the following term of Matter .
Matter—Anything that has mass and occupies space is called matter.
Define matter.
Anything that has mass and occupies space is called matter.
Define the emulsion. Give one example.
An emulsion is a colloid in which minute droplets of one liquid are dispersed in another liquid which is not miscible with it. Examples are milk and butter.
Chemical properties of matter tell us how a substance changes when it interacts with other substances. These properties describe how matter reacts and forms new substances. When a chemical change happens, the matter changes into something new. The atoms in a substance rearrange themselves, and a new substance is formed. For example:
- When wood burns, it turns into ash and smoke.
- When iron is exposed to air and water, it forms rust.
Examples of Chemical Properties:
- Flammability: This describes if a substance can burn. For example, wood is flammable because it can catch fire.
- Reactivity: This tells us how a substance reacts when mixed with others. For example, if you mix vinegar with baking soda, they react to create bubbles.
- Rusting: Some metals, like iron, will form rust when they come in contact with water and air.
- Acidity and Basicity: Some substances are acidic (like lemon juice), while others are basic (like soap). Acids and bases can react with each other to form new substances.
Define interconversion of states of matter.
The process by which matter changes from one state to another and back to the original state, without any change in its chemical composition.
Define matter
Anything that has mass and occupies space is called matter.
When two dry bodies are rubbed together, they get charged due to the movement of free electrons from one body to the other body, so they possess electrical energy.
Key Points
| Property | Solid | Liquid | Gas |
|---|---|---|---|
| Mean molecular separation | ~3–5 Å | ~3–10 Å | >5 Å |
| Particle arrangement | Tightly packed, regular | Loosely packed, irregular | Highly irregular |
| Particle movement | Fixed positions, cannot move freely | Moves a small distance within liquid | Continuous random motion |
| Shape & volume | Definite shape and volume | Takes shape of container, definite volume | Takes shape and volume of container |
| Intermolecular space | Very small | Moderate | Large |
| Effect of temperature | Small volume change | Moderate volume change | Significant volume change |
| Compressibility | Practically incompressible | Slightly compressible | Highly compressible |
| Example | A piece of iron | Water, spirit, oil | Air |
- Meaning of Energy Resources: Energy is essential for all activities like heating, running machines and generating electricity.
- Types of Energy Resources: Energy resources are classified into renewable (can be used repeatedly) and non-renewable (get exhausted after continuous use).
- Conventional Sources of Energy: These are traditional sources used for a long time, such as coal, petroleum and natural gas. They are non-renewable, exhaustible and polluting. Hydel power is an exception.
- Non-Conventional Sources of Energy: These are renewable and inexhaustible sources like solar, wind, tidal, geothermal, nuclear and biogas energy.
- Importance for India: Energy resources play a crucial role in India’s economic development, and their proper and efficient use is very important.
