Question

Which of these four elements is the most reactive
1: Na
2: Al
3: Rb
4: In

Answer 1

1: Na

Step-by-step explanation:

Out of the four elements, the most reactive element is sodium (Na).

Sodium is a highly reactive metal because it has only one valence electron in its outermost shell, which is relatively far from the positively charged nucleus. This makes it easy for sodium to lose its outermost electron and form a positively charged ion, which is why it readily reacts with other elements.

Aluminum (Al), rubidium (Rb), and indium (In) are also reactive metals, but they are less reactive than sodium.