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:

increase

decrease

greater

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.

part b. complete the sentences to identify the trend in first ionization energies as one moves across the fourth period from k to kr and explain how this trend compares with the trend in atomic radii.

complete the sentences using this word bank:

increase

decrease

less

more

1. moving from k to kr across a row, first ionization energies slightly.

2. moving from k to kr across a row, atomic radii

3. the relationship between atomic radii and first ionization energy going across a row is best explained by the fact that as atom size decreases it takes energy to completely remove an electron from the atom.

Part A

1. decrease

2. increase

3. smaller / smaller

Part B

1. increase

2. decrease

3. more

Explanation:

First ionization energy is the energy required to remove an electron from a gaseous neutral atom.

X(g) + 1 I.E. ⇒ X⁺(g) + 1 e⁻

The atomic radius is the distance from the center of the nucleus to the boundary of the surrounding shells of electrons.

Atoms with large atomic radii have low first ionization energies (and viceversa) because the electrons are far from the nucleus and the electrostatic attractions from the positive nucleus are not so strong, which results in low energy required to remove the first electron.

Part A

1. Moving from F to I in group 7A, first ionization energies decrease.

2. Moving from F to I in group 7A, atomic radii increase.

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 smaller the electrostatic attraction of an outer electron for the nucleus and the smaller the ionization energy of the element.

Part B

1. Moving from K to Kr across a row, first ionization energies increase slightly.

2. Moving from K to Kr across a row, atomic radii decrease.

3. The relationship between atomic radii and first ionization energy going across a row is best explained by the fact that as atom size decreases it takes more energy to completely remove an electron from the atom.