Exploring States of Matter

What are the three main states of matter?

• Solid, Liquid, Gas

• Solid, Liquid, Plasma

• Liquid, Gas, Plasma

• Solid, Gas, Plasma

Answer explanation

The three main states of matter are Solid, Liquid, and Gas. Solids have a definite shape, liquids take the shape of their container, and gases fill the available space. Plasma is a fourth state but not one of the main three.

Which phase change occurs when a solid turns directly into a gas?

• Condensation

• Sublimation

• Deposition

• Melting

Answer explanation

Sublimation is the phase change where a solid transitions directly into a gas without becoming a liquid first. This process is commonly observed in substances like dry ice (solid CO2) that sublimate at room temperature.

What is the process called when a gas turns into a liquid?

• Freezing

• Melting

• Condensation

• Evaporation

Answer explanation

The process when a gas turns into a liquid is called condensation. This occurs when gas molecules lose energy and come together to form a liquid, contrasting with evaporation, which is the transition from liquid to gas.

Which of the following is an example of deposition?

• Water vapour turning into dew

• Frost forming on a cold surface

• Ice melting into water

• Water boiling into steam

Answer explanation

Frost forming on a cold surface is deposition, where water vapor changes directly into solid ice without becoming liquid first. This contrasts with the other options, which involve melting or boiling.

At what temperature does water boil at standard atmospheric pressure?

• 0°C

• 50°C

• 100°C

• 150°C

Answer explanation

Water boils at 100°C under standard atmospheric pressure (1 atm). This is a fundamental property of water, making 100°C the correct answer.

What is the term for the change of state from liquid to gas?

• Freezing

• Melting

• Evaporation

• Condensation

Answer explanation

The term for the change of state from liquid to gas is evaporation. This process occurs when molecules in a liquid gain enough energy to enter the gas phase, distinguishing it from freezing, melting, and condensation.

Which state of matter has a definite shape and volume?

• Solid

• Liquid

• Gas

• Plasma

Answer explanation

A solid has a definite shape and volume, meaning it maintains its form and does not change unless acted upon by an external force. In contrast, liquids take the shape of their container, and gases and plasma do not have a definite shape or volume.

What happens to the particles of a substance as it melts?

• They move closer together

• They move further apart

• They stop moving

• They become charged

Answer explanation

As a substance melts, its particles gain energy and move further apart, transitioning from a solid to a liquid state. This increased movement allows them to overcome the forces holding them together in the solid form.

Which phase change is the reverse of sublimation?

• Freezing

• Melting

• Deposition

• Evaporation

Answer explanation

Sublimation is the process where a solid turns directly into a gas. The reverse of this process is deposition, where a gas transforms directly into a solid, making deposition the correct answer.

What is the process called when a liquid turns into a solid?

• Freezing

• Melting

• Evaporation

• Condensation

Answer explanation

The process when a liquid turns into a solid is called freezing. During freezing, the temperature drops, causing the molecules in the liquid to slow down and arrange into a solid structure.