The list which contains only metals is

Hydrogen in its metallic state (usually considered a nonmetal)

Lithium.

Sodium.

Potassium.

Rubidium.

Cesium.

Francium.

Explanation:

The list of elements that contains only metals is tin, copper and cesium.

Carbon and iodine aren't metals.

Helium isn't metal.

Neither iodine, carbon, nor argon are metals.  

(Hope this helps) Sky

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.

answer7,570,82356 cubic centimeters;