Matter and thermal energy
t
a
the
o
directions: look carefully at the graph. it was drawn from the data collected when a substan
constant rate. to heat at a constant rate means to add heat evenly as time passes. use the
g
paragraphs that follow.
temperature (°c)
liquid
solid
0
1
2
3
4
5
11
12
13 14 15
16
6 7 8 9 10
time (minutes)
3.
soog
is
hill, a division of the mcgraw-hill companies, ine.
at the start of observations, point a, the substance exists in the 1. solid
state. the temperature at this point is 2._ 10
_. as energy is absorbed, the
temperature of the substance rises at a constant rate for two minutes. at point b, the temperature is
and the solid begins to 4. melt paint . the
temperature remains constant until the change from solid to 5. liquid
complete. it has taken three minutes to add enough energy to melt the solid completely. from
point c to point d, the substance is in the 6._lionid
state. its temperature rises
at a constant rate to 7.
the temperature remains constant while the
liquid changes to a 8._ as
. at point e, the substance exists as a
9._mentha point . its temperature rises evenly as energy is added.
when the gaseous substance is allowed to cool, it releases energy. the cooling curve will
be the reverse of the warming curve. energy will be released as the substance changes
from a 10.
to a 11.
and also from a
12.
to a 13.
the amount of energy released
dusing condensation will be the same as the amount absorbed during vaporization.
copyright glencoe/mcgw
solids, liquids, and gases
23