What does it mean for metal ores to be considered limited resources?

Metal ores are considered limited resources because they are finite in nature, meaning there is a limited supply available on Earth. Once these ores are depleted through mining and extraction, they cannot be replenished within a human timescale.

A strong answer should directly address the approved learning objective to explain that metal ores are limited resources. This question belongs to Alternative methods of extracting metals within Using the Earth's resources and obtaining potable water, so the response should use that exact curriculum context rather than a generic statement. The answer is correct when it names the key idea, explains the link to limited resources, and keeps the wording specific to AQA GCSE revision.