Aluminum cookwar cannot be used in cooking acidic food .Why?It is possible to clean an aluminium pot using an oven cleaner contaning sodium hydroxide?Explain.

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Explanation:

Aluminium is an amphoteric metal. This means that it reacts with both acids and bases. This property of aluminium is important in the discussion below.

Aluminium cookers can not be used to cook acidic food because it will react with the food and this is not good both for the food and the cooker.

Also, It is not possible to clean an aluminium pot with sodium hydroxide because the sodium hydroxide will react with the pot yielding hydrogen gas since aluminium is amphotheric as follows;

2Al + 2NaOH + 2H2O → 2NaAlO2 + 3H2

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.