Hydrogen is unique among the elements because _.
1) It has only one valence electron.
2) It is the only element that can emit an atomic spectrum.
3) Its electron is not at all shielded from its nucleus.
4) It is the lightest element.
5) It is the only element to exist at room temperature as a diatomic gas.
A) 1, 2, 3, 4
B) 1, 3, 4
C) 1, 2, 3, 4, 5
D) 3, 4
E) 2, 3, 4

Question

Quizplus · Accepted Answer

Hydrogen's electron is not shielded from its nucleus because it has only one electron, and it is the lightest element.

Hydrogen Is Unique Among the Elements Because _