Question

which of the following elements is a halogen at room temperature and is located in period 3?
aluminum
krypton
sulfur
chlorine

Explanation:

• Aluminum: It is a metal in group 13 (not a halogen).
• Krypton: It is a noble gas in group 18 (not a halogen).
• Sulfur: It is a non - metal in group 16 (not a halogen).
• Chlorine: Halogens are in group 17. Chlorine (\(Cl\)) is in period 3 (third row of the periodic table) and is a halogen (\(Cl_2\) is a gas at room temperature).

Answer:

Chlorine