Explain why calcium metal after reacting with water starts floating on its surface. write the chemical equation for this reaction. name one more metal that starts floating after sometime then floats with water.

Firstly, the chemical equation between the calcium metal and water will be:  

Ca(s) + 2 H₂O(l) → Ca(OH)₂(aq) + H₂(g)  

We can see from the equation the bubbles of hydrogen gas which are formed during the reaction stick to the surface of the metal and hence calcium floats on water.  

The other metal that will float on the water during the reaction is magnesium which have the same chemical behavior like calcium, we can illustrate that by the chemical equation:

Mg(s) + 2 H₂O(l) → Mg(OH)₂(aq) + H₂(g)

n+h→nh3

we must remember that nitrogen and hydrogen are both diatomic molecules in their standard gas form. this adjusts the equation to

n2+h2→nh3

now we need to adjust coefficients in order to balance the atoms on each side of the equation. currently we have 2 atoms of nitrogen and 2 atoms of hydrogen on the reactant side and 1 atom of nitrogen and 3 atoms of hydrogen on the product side.

we can balance the hydrogens by placing a coefficient of 2 in front of ammonia and a coefficient of 3 in front of the hydrogen.

n2+3h2→2nh3

this gives us 6 hydrogen on each side and coincidentally the nitrogens now equal 2 on each side.

3 1/4 %

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