How elements are arranged in the groups of periodic table

Explanation:

The chemical elements are arranged in order of increasing atomic number. The horizontal rows are called periods and the vertical columns are called groups. Elements in the same group have similar chemical properties. This is because they have the same number of outer electrons and the same valency.

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.