Question

1. the alkaline earth metals are in group ____. (1pts)

□ 1a
□ 2a
□ 3a
□ 7a

1. which element forms diatomic molecules? (1pts)

□ carbon
□ nitrogen
□ helium
□ sulfur

1. which of the following is a member of noble gases? (1pts)

Explanation:

1. Alkaline earth metals are defined as the group 2A (or group 2) elements in the periodic table, which include beryllium, magnesium, calcium, strontium, barium, and radium.
2. Diatomic molecules consist of two atoms bonded together. Nitrogen naturally exists as $\text{N}_2$, a diatomic molecule; carbon, helium, and sulfur do not form stable diatomic molecules under standard conditions.
3. Noble gases are the group 18 elements, which include helium, neon, argon, krypton, xenon, and radon. Carbon, nitrogen, and sulfur are not noble gases.

Answer:

1. 2A
2. nitrogen
3. helium