Matter and Its Composition
Definitions :
Matter: Matter is anything that has mass, occupies space and can be perceived by our senses.
Mass: The quantity of matter that a body contains is known as its mass.
Volume: The space occupied by a body is called its volume.
Atom: An atom is the smallest possible unit of matter that exhibits all the properties of that matter. Atoms usually do not have an independent existence.
Molecule: A molecule is the smallest unit of matter which exhibits all the properties of that kind of matter and also has an independent existence. A molecule can be formed of the atoms of the same kind (For e.g H2, N2) or of the different kinds ( H2O, CO2).
Inter-particular or Intermolecular Space: Particles of matter have space between them. This space is called inter-particular or intermolecular space.
The intermolecular force of attraction: The force of attraction existing between the particles or molecules if matter, which holds them together is called the intermolecular force of attraction.
Fluids: All substances that can flow are called fluids. Liquids and gases are fluids.
Interconversion of States of Matter: It is a process by which matter changes from one state to another and back to the original state without any change in its chemical composition when conditions are changes.
Sublimation: It is a process in which a substance changes directly from solid state to the vapour state.
Name two objects made up of each of the following materials:
- Metal: Gold jewellery, iron bars
- Wool: Sweater, scarf
- Cloth: Shirt, Pant
- Plastic: Bucket, toys
- Leather: Shoes, bags
Write a short note on Newton(N).
Newton is a standard Unit (S.I unit) of force and is denoted by letter N. It is named after Sir Issac Newton, a famous scientist in recognition of his work in classical mechanics.
Why do particles of matter move?
The particles of matter possess kinetic energy. The kinetic energy increases with the increase in the temperature and decreases with the decrease in the temperature. Hence the movement of particles of matter increases or decreases with the increase or decrease in the temperature respectively.
What are the three main characteristics of the particles of matter?
The three main characteristics of particles of matter are
- Particles of matter have space between them which is called intermolecular space.
- Particles of matter are always in random motion.
- Particles of matter attract each other because of the intermolecular force of attraction.
Why liquids are called fluids?
The particles in the liquid are less tightly packed in comparison to solids. in liquids, the intermolecular force of attraction is weaker and intermolecular gaps are larger. Hence the particles are free to move within the bulk and thus liquid can flow. Therefore liquids is called fluids.
What is Sublimation and name the three substances which can go through the process of sublimation?
Sublimation is a process in which a substance changes directly from the solid state to the vapour state.
Example: Camphor, naphthalene, iodine crystals, ammonium chloride etc.
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