Select the correct number of valence electrons, in order, for groups 13-18. 13, 14, 15, 16, 17, 18
5, 6, 4, 3, 8,7
3,4,5,6,7,8
18, 13, 15, 16, 17, 14

3,4,5,6,7,8

Explanation:

Groups 13  - 18 are the main group on the periodic table

The group number corresponds the number of valence electrons they contains.

Valence electrons are the number of electrons in the outermost shell of an atom.

So group 13 - 18 corresponds to a valency of 3,4,5,6,7,8.

Groups with a valency of 8 are the noble gases.

answer: - 3.) the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

solution: - as per the rules, oxidation number of oxygen in its compounds is -2. the sum of oxidation numbers of all the elements of a molecule or compound is zero.

also, the oxidation number in elemental form is zero.

in no, the oxidation number of o is -2 so the oxidation number of n is +2 so that the sum is zero.

similarly, the oxidation number of c in co is +2 and o is -2.

on product side the oxidation number of n is 0 as it is in the elemental form() .

oxidation number of c in carbon dioxide is +4 as there are two oxygen in it and we know that each oxygen is -2.

so, oxidation number of n is changing from +2 to 0 and the oxidation number of c is changing from +2 to +4.

since nitrogen is reduced and hence no is acting as an oxidizing agent. carbon is oxidized and so co is acting as a reducing agent.

so, the right choice is number 3.)the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

it would be d. henry moseley

hope this !

and sorry if i'm late. have a good rest of your day! : d