Ch.6.4

Question 1

The ________________ of the particles of a substance is related to its ________________. When the temperature is ________________, the particles move ________________. When the temperature is ________________, the particles move ________________.

Answer 1

movement, temperature, higher, faster, lower, slower

Question 2

From the movement of particles, we can understand the ________________ __________ _________ _____________ _______ _____ ________________ when it is ________________ or ________________.

Answer 2

change in the size of a substance, heated, cooled

Question 3

When a substance is heated, its particles move ________________. Therefore, the particles are ________________ ________________ and the substance as a whole ________________ ________ ________________.
Similarly, when a substance is ________________, its particles move ________________ and become ________________ ________________, causing the substance as a whole to ________________ ________ ________________.

Answer 3

faster, further apart, increases in size

cooled, slower, closer together, decrease in size

Question 4

Most substances expand ________ ________________ and ________________ _______ ________________. This is called ________________ ________________ ________ ________________.

Answer 4

on heating, contract on cooling, thermal expansion and contraction