Question

q.14. when the particles are ____, they gain energy and move faster.
a) heated b) cooled
q.15. which state of matter has the most energy?
a) solid b) liquid c) gas
q.16. which of the following does not take the shape of its container?
a) gasoline b) pencil
c) oxygen d) juice
q.17. what is the name of the process when a gas turns into a liquid?
a) melting b) evaporation
c) condensation d) freezing
q.18. what is the name of the process when a liquid turns into a solid?
a) melting b) evaporation
c) condensation d) freezing
q.19. what is the name of the process when a solid turns directly into a gas?
a) sublimation b) deposition
c) evaporation d) condensation
q.20. a matter has a melting point of -25°c, and a boiling point of 46°c. what state will it have at a temperature of 53°c?
a) solid b) liquid c) gas
q.21. a matter has a melting point of 10°c, and a boiling point of 95°c. what state will it have at a temperature of 53°c?
a) solid b) liquid c) gas
q.22. the table shows the melting points and boiling points for different substances. identify the state of given substances at room temperature (room temperature is around 20°c).

Explanation:

• Q.14: When particles are heated, they gain energy and move faster. Cooling reduces particle energy and movement.
• Q.15: Gas particles have the most energy as they move freely and rapidly compared to solids (least energy) and liquids.
• Q.16: Solids (like a pencil) have a fixed shape and do not take the shape of their container. Liquids (gasoline, juice) and gases (oxygen) take the shape of their container.
• Q.17: Condensation is the process where a gas turns into a liquid. Melting is solid to liquid, evaporation is liquid to gas, and freezing is liquid to solid.
• Q.18: Freezing is the process when a liquid turns into a solid. Melting is solid to liquid, evaporation is liquid to gas, and condensation is gas to liquid.
• Q.19: Sublimation is when a solid turns directly into a gas. Deposition is gas to solid, evaporation is liquid to gas, and condensation is gas to liquid.
• Q.20: A matter with a boiling point of \(46^{\circ}C\) will be a gas at \(53^{\circ}C\) (above boiling point).
• Q.21: A matter with a melting point of \(10^{\circ}C\) (solid below \(10^{\circ}C\)) and boiling point of \(95^{\circ}C\) (liquid between \(10^{\circ}C - 95^{\circ}C\)) will be a liquid at \(53^{\circ}C\).
• Q.22:
• Water: Melting point \(0^{\circ}C\) (solid below \(0^{\circ}C\)), boiling point \(100^{\circ}C\) (liquid between \(0^{\circ}C - 100^{\circ}C\)). At \(20^{\circ}C\) (room temp), it is liquid.
• Oxygen: Boiling point \(- 183^{\circ}C\) (gas above \(-183^{\circ}C\)). At \(20^{\circ}C\), it is gas.
• Iron: Melting point \(1538^{\circ}C\) (solid below \(1538^{\circ}C\)). At \(20^{\circ}C\), it is solid.
• Sulfuric acid: Melting point \(10.3^{\circ}C\) (solid below \(10.3^{\circ}C\)), boiling point \(337^{\circ}C\) (liquid between \(10.3^{\circ}C - 337^{\circ}C\)). At \(20^{\circ}C\), it is liquid.
• Magnesium: Melting point \(650^{\circ}C\) (solid below \(650^{\circ}C\)). At \(20^{\circ}C\), it is solid.
• Nitrogen: Boiling point \(-195^{\circ}C\) (gas above \(-195^{\circ}C\)). At \(20^{\circ}C\), it is gas.

Answer:

• Q.14: a) heated
• Q.15: c) Gas
• Q.16: b) Pencil
• Q.17: c) Condensation
• Q.18: d) Freezing
• Q.19: a) Sublimation
• Q.20: c) gas
• Q.21: b) liquid
• Q.22:
• Water: liquid
• Oxygen: gas
• Iron: solid
• Sulfuric acid: liquid
• Magnesium: solid
• Nitrogen: gas