As a substance changes phase from a gas to liquid to solid:
a- the spacing between molecules increases.
b- it's density generally increases.
c- the spacing between molecules is not affected.
d- it undergoes chemical change.

Which statement best describes the oxidation numbers of the atoms found in magnesium chloride? a. magnesium has a 2- oxidation number and chlorine has a 1+ oxidation number. b. magnesium has a 2- oxidation number and chlorine has a 2+ oxidation number. c. magnesium has a 2+ oxidation number and chlorine has a 1- oxidation number. d. magnesium has a 1+ oxidation number and chlorine has a 1- oxidation number.

What is the ph of a 0.0010 m hno3? 1.0 3.0 4.0 5.0

How does carbon monoxide pose the greatest threat to humans? a. it can be produced by wood fires. b. it can be produced by home furnaces. c. it is produced by acid rain. d. it is produced by modern automobiles.