Question

q.5. write t or true if the statement is true; write f or false if the statement is false.

1. heat is a form of energy, and it is measured in joules.
2. molecules with less heat energy move faster.
3. heat transfer will continue until the objects are the same temperature.
4. radiation requires particles to travel.
5. gases are better conductors than liquids or solids.

q.6. which of the following term is used for materials that conduct heat poorly?
a) conductor b) insulator c) thermometer d) metals
q.7. which of the following is the best conductor of heat?
a) plastic b) glass c) metals d) wood
q.8. ____ is a measure of the average kinetic energy of all the particles in a substance.
a) temperature b) heat c) expansion d) deduction
q.9. when air warms up the air molecules move ____.
a) slower b) faster
q.10. when air cools down the air molecules move ____.
a) slower b) faster
q.11. during day, air over the land is warmer than the air over the sea in coastal areas. warmer air rises, cooler air sinks and the process continues.
what heat transfer process is occurring here?
a) conduction b) radiation c) convection
q.12. what type of heat transfer can occur in a vacuum? (there are no particles in a vacuum.)
a) conduction b) radiation c) convection
q.13. ironing clothes is an example of what type of heat transfer?
a) conduction b) radiation c) convection
q.14. a hot air balloon rising is an example of what type of heat transfer?
a) conduction b) radiation c) convection

Explanation:

1. Heat is a form of energy and joules is its SI - unit, so it's true.
2. Molecules with more heat energy move faster, so this is false.
3. Heat transfer occurs until thermal equilibrium (same temperature) is reached, so it's true.
4. Radiation is the transfer of energy in the form of electromagnetic waves and does not require particles, so this is false.
5. Solids (especially metals) are better conductors than liquids and gases, so this is false.

For Q.6: Insulators are materials that conduct heat poorly.
For Q.7: Metals are the best conductors of heat among the given options.
For Q.8: Temperature is a measure of the average kinetic energy of particles in a substance.
For Q.9: When air warms up, air molecules gain energy and move faster.
For Q.10: When air cools down, air molecules lose energy and move slower.
For Q.11: The movement of warm air rising and cool air sinking is convection.
For Q.12: Radiation can occur in a vacuum as it does not rely on particles.
For Q.13: Ironing clothes involves direct contact, which is conduction.
For Q.14: A hot - air balloon rising is due to the movement of warm air, which is convection.

Answer:

Q.5:

1. T
2. F
3. T
4. F
5. F

Q.6: b) Insulator
Q.7: c) Metals
Q.8: a) Temperature
Q.9: b) faster
Q.10: a) slower
Q.11: c) Convection
Q.12: b) Radiation
Q.13: a) Conduction
Q.14: c) Convection