true or false? covalent compounds mainly contain elements in groups 1 and 2 of the periodic table.

False. Covalent compounds mainly contain non-metal elements, which are mostly in groups 14–17 (and hydrogen), not in groups 1 and 2.

Why the statement is false

• Groups 1 and 2 are the alkali metals and alkaline earth metals, which tend to form positive ions and make ionic compounds with non-metals.

• Covalent compounds form when atoms share electrons, which most commonly happens between non-metal atoms located toward the right side of the periodic table (roughly groups 13–18, plus hydrogen).

Quick examples

• Typical covalent compounds:
  • Water, H2O\text{H}_2\text{O}H2​O: hydrogen (often treated with non-metals) + oxygen (group 16).

* Carbon dioxide, CO2\text{CO}_2CO2​: carbon (group 14) + oxygen (group 16).

• Typical compounds of groups 1 and 2 (like NaCl, MgO) are ionic, not covalent, because metals transfer electrons to non-metals instead of sharing them.

So the correct answer to “true or false? covalent compounds mainly contain elements in groups 1 and 2 of the periodic table” is: False.

Information gathered from public forums or data available on the internet and portrayed here.