Use the periodic table to determine the electron configuration for aluminum (al) and arsenic (as) in noble-gas notation.

Electronic configuration of

1. Aluminium is

2. Arsenic is

Explanation: To write the electronic configuration of the elements in the noble gas notation, we first count the total number of electrons and then write the noble gas which lies before the same element.

Atomic number = 13

Total number of electrons = 13

Noble gas which lies before this element is Neon (Ne).

Neon has 10 electrons, rest 3 electrons are filled in 3s and 3p sub-shells.

Electronic configuration of Aluminium becomes

Atomic number = 33

Total number of electrons = 33

Noble gas which lies before this element is Argon (Ar).

Neon has 18 electrons, rest 15 electrons are filled in 4s , 3d and 4p sub-shells.

Electronic configuration of Arsenic becomes .

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.