Select the word that is spelt INCORRECTLY.

Concept

A spelling question tests whether each word matches its standard dictionary form. The task is to spot the single word whose letter sequence does not correspond to any accepted English spelling, while the rest are all valid words.

Application

Checking each word against standard English: "moltan" is not a recognised English word. The intended word is "molten" (meaning melted, as with rock or metal), which is spelt with "-ten", not "-tan". Replacing the "a" with the correct "e" gives the valid form, so "moltan" is the misspelt entry.

Cross-check

The remaining words are all correctly spelt:

• "moist" — correctly spelt; means slightly wet or damp.

• "molest" — correctly spelt; means to bother, harass or interfere with someone.

• "molecule" — correctly spelt; means the smallest unit of a substance that retains its properties.

Since these three are valid dictionary words and only "moltan" is not, "moltan" is the incorrectly spelt word.