AQAGCSEChemistryFoundation1 mark
GCSE revision question
Question context
A corrosion experiment measures the rate at which iron rusts at 0.25 mm per year. The thickness of the iron sheet is 5 mm.
State the unit used to express the corrosion rate.
Show answer, mark scheme and Mentor explanation
Answer and mark-scheme guidance
MP1: Unit = mm/year (millimetres per year).
Mentor — AI Tutor
Can you secure the mark by naming the unit exactly?
This 1-mark question is testing whether you can state the unit used for a corrosion rate. The mark scheme accepts mm/year, which means millimetres per year. To get the mark, your answer needs that unit.
Quick takeaway: For the corrosion rate, the mark is for mm/year (millimetres per year).