Question

a metal surface is cleaned by rubbing with Sandpaper to remove a layer of its________.

Answer 1

This is done to remove an oxide layer formed by the metal due to reaction with atmospheric oxygen or sometimes even carbon dioxide

Answer 2

Magnesium ribbon should be cleaned before burning in air this is because it has an oxide coating on it which prohibits its reaction with air or we can say that it slows down the reaction taking place.

Therefore, it should be cleaned before burning in air.

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