Words / B2

HYDR-uh-j-uh-n/ˈhaɪdrədʒən/

Hydrogen is a colourless gas, the lightest chemical element (symbol H), that combines with oxygen to make water: hydrogen gas; a hydrogen fuel cell. H₂ is the molecule; the squeaky-pop test is the school practical. Write the hydrogen test in the practical, not a fuel-cell advert. Mix-up: nitrogen / oxygen (already related); hydrate. Do not write hydrogen for a hydrocarbon fuel unless the source names H₂.

Meaning

A colourless gas, the lightest chemical element (symbol H), that combines with oxygen to make water.

Examples

• “Write the hydrogen test in the practical (the squeaky pop), not a fuel-cell advert.”
• “A hydrogen fuel cell featured in the energy case, which is the technology sense — still name the efficiency if given.”

Good to know

hydrogen gas; H / H₂; hydrogen fuel cell; the squeaky-pop test. Trap: nitrogen / hydrocarbon. Chemistry and geography. The lightest element, a colourless gas — not a slogan.

Near in meaning

H, H₂

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