Properties of Matter - Science
- A substance made up of atoms that have a mass and occupy space is called matter.
- Matter can exist in three forms, i.e. solid, liquid, gas.
- Atoms are the fundamental structures of matter that combine to form molecules. These atoms cannot be further broken into smaller particles.
- All states of matter have different properties and are interconvertible.
Atoms and Molecules
Question 1:
What Are Atoms? Why Are They Called the Basic Structures of Matter?
Answer:
- Atoms are the smallest indivisible parts of matter.
- Atoms are elementary particles which come together to form molecules which combine to form matter.
- Since an atom cannot be divided further into small particles, it is called the basic structure of matter.
Question 2:
Does the Atom or the Molecule of a Particular Matter Have Its Own Colour?
Answer:
- Atom or molecule does not reflect a visible light that the eyes can see.
- We cannot see the colour of a single atom or molecule, because it is too faint to be noticed by the eyes.
- Hence it can be concluded that they do not have a specific colour.
Question 3:
Why Do Oil and Water Not Mix?
Answer:
- For any liquid to dissolve in water, it should be capable of breaking the bonds between the atoms of a water molecule.
- This cannot be done by the fat or oil molecules found in oil; hence it does not dissolve in water.
Question 4:
Aluminium and Iron Are Both Metals. 1 kg of Aluminium Needs More Space Than 1 kg of Iron. Why So?
Answer:
- Iron occupies less space than aluminium as the molecules of iron metal are compactly packed, making iron dense.
- In the case of aluminium, the molecules are loosely packed. Hence, they occupy more space as compared to iron molecules.
Three States of Matter
Question 1:
Why a Solid Object Makes Noise on the Impact of Another Solid Object?
Answer:
- Sound waves are produced as a result of vibrations in any object.
- As the solid object collides with another solid object, the atoms start vibrating, which produces sound.
Question 2:
Why Does the Air Form Bubbles Inside the Water?
Answer:
Air is soluble in water. But when the amount of gas dissolved in the water exceeds its limit, the air molecules start aggregating, forming air bubbles.
Solid Liquid Gas
Question 1:
LPG and Kerosene Are Fuels; Why Do We Use LPG in Metal Cylinders While Kerosene Can Be Kept in Closed Containers?
Answer:
- LPG and kerosene are both highly inflammable fuels.
- It is possible to safely handle LPG (Liquefied Petroleum Gas) when it is in liquid form. But to store it in liquid form, high pressure must be maintained; hence it is stored in metal cylinders.
- There is no such requirement for kerosene; hence it can be stored in any plastic container.
Question 2:
Is Plasma a State of Matter? How Is It Formed, and Where Is It Used?
Answer:
- Yes, plasma is the fourth state of matter.
- Plasma is formed on heating, the gas at a very high-temperature
- Plasma is used in fluorescent lights, neon lights and LED screens.
Question 3:
What Is Dry Ice? How Is It Different From Regular Ice?
Answer:
- Dry ice is the solid carbon dioxide stored at extremely low temperatures.
- When it comes to normal temperature, this dry ice directly converts into carbon dioxide gas, unlike regular ice. Hence it is called dry ice.
Question 4:
Solid Water Can Be Changed Into Liquid or Gas and Again Into Solid Ice. But a Baked Cake Cannot Be Separated Into Flour, Water and Other Ingredients. Why?
Answer:
- Solid water can be changed into liquid or gas as it is a change which does not change the properties of water permanently; hence it can be reversed.
- In the case of baking cake, the properties of ingredients change permanently and cannot be reversed in any condition.
