Ionization Energy Trends Worksheet

Question 1

Which process represents the first ionization of a sodium atom?

1. Na(g) → Na⁺(g) + e⁻
2. Na⁺(g) + e⁻ → Na(g)
3. Na(g) + e⁻ → Na⁻(g)
4. Na⁺(g) → Na²⁺(g) + e⁻

Question 2

Potassium is one period below sodium in Group 1. Explain why potassium’s first ionization energy is lower.

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Question 3

Which change generally makes an electron harder to remove when other factors are similar?

1. Weaker attraction to the nucleus
2. Stronger attraction to the nucleus
3. Greater distance from the nucleus
4. Greater shielding by inner electrons

Question 4

Across a period, the outermost electrons are generally in the same principal energy level. Explain why first ionization energy often rises from left to right.

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Question 5

Which element in the table needs the least energy to lose its first electron?

1. Na
2. Mg
3. Al
4. Si

Question 6

By how much does first ionization energy decrease from Mg to Al? Include units.

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Question 7

Use the orbital information to explain why Al has a lower first ionization energy than Mg despite having one more proton.

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Question 8

Which statement correctly summarizes the four measurements?

1. Energy rises at every step.
2. Energy falls at every step.
3. Energy rises from Na to Si overall, with a decrease from Mg to Al.
4. The values are the same for Na and Si.