When studying the halogens (group 17) on the periodic table, how does the number of the valence electrons change as the energy level is increased? a) the total number of valence electrons does not change, it remains 7. b) the total number of valence electrons does not change, it remains 1. c) the total number of valence electrons increases by 1 with each energy level. d) the total number of valence electrons decreases by 1 with each energy level.

The correct answer is Option A.

Explanation:

Elements that are present in Group 17 are Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I) and Astatine (At).

The general electronic configuration for these elements are:

Where,

n = principle quantum number or the number of period to which the element belongs.

In the electronic configuration, the noble gas which is present in the proceeding period.

The valence electrons are defined as the number of electrons which are present in the outermost shell.

Number of valence electrons for this group are 7. In a period, the valence electrons remains constant.

Hence, the correct answer is Option A.

- calcium has greater affinity to bond with electron receptors than hydrogen does and hence, it has the ability to replace hydrogen in most of its compounds.

- lithium has 2 valence electrons in the product because it can make only 1 bond with hydrogen. beryllium has 4 valence electrons in the product because it can only make 2 bonds. it has fewer electrons than neon and can react with electron donors. each hydrogen has 2 valence electrons, the same as helium.

- the covalent bond formed between carbon and hydrogen is polar because carbon is more electronegative than hydrogen and it attracts the bonded electron pair closer to itself, thus giving hydrogen a partial positive charge.

- a hydrogen bond is a relatively weak bond that hydrogen atoms make with the electronegative atoms nitrogen, oxygen or fluorine.

so the best choice is a.) 2 calcium (ca) atoms