The ……………. have more ……………. and ……………. more often, resulting in more ……………. between them. This decreases the ……………. of the air pocket, so it rises.

the correct option is c.

isotopes refers to different forms of the same element with the same atomic number but different mass number as a result of difference in their neutron numbers. isotopes have different relative atomic mass but share the same chemical properties.

if you're asking what comes out, it's steam.