Question

which element has the largest ionization energy in each pair? 1. lithium or potassium? 2. magnesium or silicon? 3. magnesium or strontium? 4. carbon or oxygen?

Explanation:

Step1: Recall ionization - energy trend

Ionization energy increases across a period and decreases down a group in the periodic table.

Step2: Compare Lithium and Potassium

Lithium (Li) is in period 2 and group 1, Potassium (K) is in period 4 and group 1. Since ionization energy decreases down a group, Li has a larger ionization - energy.

Step3: Compare Magnesium and Silicon

Magnesium (Mg) is in group 2 and period 3, Silicon (Si) is in group 14 and period 3. Since ionization energy increases across a period, Si has a larger ionization - energy.

Step4: Compare Magnesium and Strontium

Magnesium (Mg) is in period 3 and group 2, Strontium (Sr) is in period 5 and group 2. Since ionization energy decreases down a group, Mg has a larger ionization - energy.

Step5: Compare Carbon and Oxygen

Carbon (C) is in group 14 and period 2, Oxygen (O) is in group 16 and period 2. Since ionization energy increases across a period, O has a larger ionization - energy.

Answer:

1. Lithium
2. Silicon
3. Magnesium
4. Oxygen