Answer: Absorption of H 2 into metal lattice weakens metallic bonds, making the metal brittle and prone to cracking.
- A Absorption of H<sub>2</sub> into metal lattice weakens metallic bonds, making the metal brittle and prone to cracking
- B Hydrogen gas chemically reacting with the surface metal oxide layer to release water vapour as frequently observed in practice
- C The bulk metal slowly dissolving away when largely immersed in liquid hydrogen peroxide in many documented cases
- D The thermal softening effect produced by burning hydrogen gas nearby the metal surface according to conventional understanding
Correct answer: A. Absorption of H<sub>2</sub> into metal lattice weakens metallic bonds, making the metal brittle and prone to cracking
Explanation: Hydrogen embrittlement occurs when atomic H diffuses into metal (e.g., steel), occupying voids and creating internal pressure that causes cracking.
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.