Grade 7 Science- Heat and tempurature topic 5

Question 1

Heat capacity

Answer 1

amount of thermal energy required to warm or cool object by 1 degree

Question 2

melt (fusion)

Answer 2

solid to liquid-increase in in energy

Question 3

freeze (solidification)

Answer 3

liquid to solid- decrease in energy

Question 4

evaporation

Answer 4

liquid to gas-increase in energy

Question 5

condensation

Answer 5

gas to liquid-decrease in energy

Question 6

sublimation

Answer 6

gas to solid-decrease in energy

Question 7

second sublimation

Answer 7

solid to gas-increase in energy

Question 8

changes in state

Answer 8

melting-freezing-evaporation-condensation-sublimation-second sublimation

Question 9

melting point and boiling point

Answer 9

liquid gold-1064 degrees (melting point) 2856 degrees
(boiling point)
oxygen- minus 218 degrees(melting point) minus 2602 degrees(boiling point
tin-232 degrees(melting point) 2602( boiling point)

Question 10

Evaporative cooling

Answer 10

This happens when fast moving particles on the surface of a liquid escape into the air. Slower moving particles that are left behind have slower kinetic energy decreasing the temperature of the remaining liquid and the surface which it was resting on.
Examples: getting out of the shower and getting cold, cloth on forehead when having a fever, clothes drying when wet.