An atom of chromium has 24 protons, 28 neutrons, and 24 electrons. a chromium atom particles in the necleus

52

Explanation:

protons and neutrons are in the nucleus so u have to add those together

it is the most commonly accepted one

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.