1.What Is Dry Ice?
- Dry ice is the solid form of carbon dioxide.
- It looks like snow and is used as a refrigerant.
- Dry ice sublimes without melting like naphthalene.
- It is mainly used to transport meat, fish and ice cream.
2.Which Metal Is Liquid at Room Temperature?
- Mercury is a metal that exists in liquid form at room temperature.
- Mercury is a heavy metal and looks silver in colour.
- Mercury is used in thermometers to measure temperatures.
3.Do Gases Always Float Around?
- The molecules of gases have the least attractive forces between them.
- It is the reason why the molecules of gases always float around.
- If the temperature and pressure are reduced, the gas may get condensed, turn into a liquid, and not float in liquid form.
4.Why Can We Easily Compress a Gas but Not a Liquid?
- A gas can be easily compressed because the particles of a gas are not tightly packed and have large intermolecular spaces.
- On the contrary, liquids cannot be compressed easily as they have fewer intermolecular spaces than gases.
- Liquids also have a fixed volume that can be measured.
5.What Is the Hardest Substance Known on Earth? Write a Few Uses of It.
Diamond is the hardest substance on Earth.
It has the following uses:
- Diamond is a precious stone, and it is used to make pieces of jewellery.
- Diamond is used in the glass-making industry as a glass cutter.
- Diamond dust is used to make cosmetics and medicines.
6.Why Do Liquids Permanently Settle at the Bottom of the Container but Not Gases?
- Substances with higher density permanently settle first than the substances with lower density.
- Liquids permanently settle down at the bottom of the container due to the action of gravitational force on them, as they are denser than the gaseous molecules.
7.What Is the Strongest Manufactured Material?
- Graphene is the strongest manufactured material.
- It is a transparent material that is made up of carbon.
- Carbon is the structural element of charcoal and graphite.
8.Name a Few Physical Properties of Matter.
A few properties of matter are- colour, hardness, odour, mass, length and volume.