Complete the sentences to identify the trend in first ionization energies as one proceeds down the group 7A elements and explain how this trend relates to the variation in atomic radii.

Complete the following sentences using this word bank:

a. increase
b. decrease
c. greater
d. smaller

1. Moving from F to I in group 7A, first ionization energies
2.Moving from F to I in group 7A, atomic radii
3. The relationship between atomic radii and first ionization energy going down a column is best explained by the fact that the greater the atomic radius, the the electrostatic attraction of an outer electron for the nucleus and the the ionization energy of the element.

a)decrease

b)increase

c)smaller

d)smaller

Explanation:

Ionization energy decreases down the group due to increase in the atomic radius. The distance between the outermost electron and the nucleus increases hence the nuclear attraction for the outermost electrons become smaller and the ionization energy also become smaller as electrons are now easily removed from the outermost shell.

Hence the group of answer choices provided above.

answer: the enthalpy of the overall chemical reaction is +87.88 kj or +88 kj.

according to hess's law, the overall enthalpy of a reaction is the difference between the sum of enthalpy values of all the products and the sum of enthalpy values of all the reactants.

δh(reaction) = ∑nδh(products) - ∑nδh(reactants)

δh(reaction) = [δh +δh] - [δh]

δh(reaction) = [1(-287.02) + 1(0) ] - [1(-374.9)] kj = +87.88 kj

here, δh (pcl3) = -287.02 kj, δh(cl2) = 0, δh(pcl5) = -374.9 kj

therefore, enthalpy of the overall reaction is +87.88 kj or +88 kj.