Question

A student attempts to arrange four elements (as shown below) in order from most reactive to least reactive.

From most reactive to least reactive:
19 - K - 39.10
12 - Mg - 24.31
6 - C - 12.01
2 - He - 4.00

Is the arrangement correct, and why (or why not)?
(1 point)
• Yes. An element's reactivity decreases from left to right on the periodic table.
• No. An element's reactivity decreases from right to left on the periodic table.
• No. An element's reactivity decreases as atomic mass increases.
• Yes. An element's reactivity decreases along with its atomic number.

Answer 1

No. An element's reactivity decreases as atomic number increases, not as atomic mass increases. Therefore, the correct answer is:

• Yes. An element's reactivity decreases along with its atomic number.