What happens when metal reacts with water? 

Metal oxides are formed. 

The correct answer is option 2. Metal oxides are formed.

When metals react with water, the products formed depend on the reactivity of the metal:

1. Highly Reactive Metals (e.g., Group 1 metals like sodium, potassium):

Highly reactive metals react vigorously with water, producing metal hydroxides and hydrogen gas.

For example:

\[ 2\text{Na} + 2\text{H}_2\text{O} \rightarrow 2\text{NaOH} + \text{H}_2 \]

Sodium reacts with water to form sodium hydroxide (\(NaOH\)) and hydrogen gas (\(H_2\)).

2. Moderately Reactive Metals (e.g., Group 2 metals like calcium):

Moderately reactive metals also react with water, but less vigorously compared to highly reactive metals.

They form metal hydroxides and hydrogen gas as well.

For example:

\[ \text{Ca} + 2\text{H}_2\text{O} \rightarrow \text{Ca(OH)}_2 + \text{H}_2 \]

Calcium reacts with water to form calcium hydroxide (\(Ca(OH)_2\)) and hydrogen gas (\(H_2\))

3. Less Reactive Metals (e.g., Group 13 metals like aluminum):

Less reactive metals such as aluminum react with water very slowly, if at all, at normal temperatures.

They form metal oxides and hydrogen gas when they do react.

For example:

\[ 2\text{Al} + 3\text{H}_2\text{O} \rightarrow \text{Al}_2\text{O}_3 + 3\text{H}_2 \]
Aluminum reacts with water to form aluminum oxide (\(Al_2O_3\)) and hydrogen gas (\(H_2\)).

4. Unreactive Metals (e.g., noble metals like gold, platinum):

Unreactive metals such as gold and platinum do not react with water under normal conditions.

So, depending on the reactivity of the metal, the products of the reaction with water can be metal hydroxides (for highly reactive metals), metal oxides (for less reactive metals), or no reaction (for unreactive metals). Therefore, the most general answer among the options provided would be: Metal hydroxides are formed.

However, it's important to note that this is not universally true for all metals; the specific products depend on the reactivity of the metal.