How did knowing the number of valence electrons in one of the alien elements to identify it? explain how the table was used to accomplish this task.

All elements in the same group of the periodic table have the same number of valence electrons. The number of valence electrons always matches the ones place digit of the group number. Knowing the valence electrons of an alien element allows matching it with its group

Explanation:

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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.

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