Which of the following materials is useful for making molds because it has a low melting point?
a. wood
b. metal
c. clay
d. wax

The right answer is wax.

The waxes are of synthetic, natural, animal or plant origin composed of long and branched chains which gives them a microcrystalline structure. This results in a soft, white, non-translucent substance whose melting temperature is arround 70 ° C.

The melt temperature of the clay exceeds 1000 ° C.

It is clear that wood and metal are not used for low temperature molding.

the answer is   c.) 1575 j.

explanation:

the atomic number will stay the same no matter how many electrons it has, so it doesn’t decrease nor increase. it’ll only change with a different number of protons