A part of the periodic table is shown.

Question

A portion of the first two columns of the periodic table is shown. Column one from top to bottom reads 11 sodium, 19 potassium, and 37 rubidium. Column two reads 12 magnesium, 20 calcium, and 38 strontium.

Which of the following elements is more reactive than the others?

Group of answer choices

Magnesium (Mg)

Sodium (Na)

Calcium (Ca)

Potassium (K)

Answer 1

In the periodic table, reactivity varies as you move down the groups (columns).

For alkaline metals (Group 1), such as sodium (Na) and potassium (K), reactivity increases as you move down the group. Therefore, potassium is more reactive than sodium.

For alkaline earth metals (Group 2), such as magnesium (Mg) and calcium (Ca), reactivity also increases as you move down the group. Thus, calcium is more reactive than magnesium.

Now comparing sodium (Na) and potassium (K) (Group 1) with magnesium (Mg) and calcium (Ca) (Group 2):

• Potassium (K) is more reactive than sodium (Na).
• Calcium (Ca) is more reactive than magnesium (Mg).
• However, potassium (K) is more reactive than both calcium (Ca) and magnesium (Mg).

So, the element that is more reactive than the others listed is Potassium (K).