<span>A physical change basically involves a change in physical properties. Some examples of physical properties include: texture, shape, size, color, volume, mass, weight, etc.
The water melting has changed the shape and therefore it's physical properties, but the chemical nature of the water has not been altered.
So that's why it's a physical change, and not a chemical change.</span>
It would be any white dwarf star
<span>The reaction is N2 + 3H2 -> 2NH3
So the amount of NH3 formed is 2/3 of the amount of H2 = 2/3 * 13.7 = 9.13 Liters.</span><span>The answer is 9.13
</span>