Maheswari

• Solid – Has a fixed shape and fixed volume. Its particles are packed closely together and mainly vibrate in place.

• Liquid – Has a fixed volume but no fixed shape. It takes the shape of its container, and its particles can move past one another.

• Gas – Has no fixed shape or volume. Its particles are far apart and move freely in all directions.

• Plasma – A very high-energy state of matter made of charged particles. It occurs naturally in things like stars and lightning.

• Bose–Einstein condensate (BEC) – Forms at extremely low temperatures. Particles behave collectively as though they are one quantum system.

• Superfluid – A special state of matter that can flow with extremely little resistance. It occurs at very low temperatures.

1. Epidermis

The epidermis is the plant's outer covering.

• Protects the plant from damage

• Helps reduce water loss

• In roots, it helps absorb water and minerals

• In leaves, it contains stomata for gas exchange

A chemical reaction is when one or more substances change into completely new substances.

Example:

When you burn wood:

• Wood + oxygen → ash + gases

• The new substances have different properties from the wood.

Key points:

Definition

A journey into space is the travel of astronauts or spacecraft beyond Earth's atmosphere to explore space, conduct scientific research, and learn more about the universe.

Key Points

• Space travel begins with the launch of a rocket.

• Astronauts travel in a spacecraft.

• In space, astronauts experience microgravity, which makes them feel weightless.