Answer: Carbon, a p-block non-metal.
- A Sodium, a reactive s-block metal
- B Calcium, an alkaline earth metal
- C Carbon, a p-block non-metal
- D Potassium, a soft alkali metal
Correct answer: C. Carbon, a p-block non-metal
Explanation: p-block non-metals such as carbon form covalent molecular hydrides; s-block metals like Na, K and Ca form ionic (saline) hydrides instead.
Each water molecule's O-H bonds (covalent, solid) can hydrogen-bond (dashed) to neighbouring molecules, forming an extended network responsible for water's unusually high boiling point and density anomaly.
Concept context
The simplest and most abundant element in the universe. Study its unique position in the periodic table, isotopes (protium, deuterium, tritium), properties of water and hydrogen peroxide, and industrial uses.