The average kinetic energy of water molecules increases when - a: h2o(s) changes to h2o(l) at 0°c b: h2o(l) changes to h2o(s) at 0°c c: h2o(l) at 10°c changes to h2o(l) at 20°c d: h2o(l) at 20°c changes to h2o(l) at 10°c

option C: H2O(l) at 10°C changes to H2O(l) at 20°C


Explanation:

To solve this questions use the fact the temperature is a measure of the average kinetic energy of the particles of a substance.

For a given substance, the higher the temperature the higher kinetic energy, the lower the temperature the lower the kinetic energy

That is a statement derived from the kinetic theory.

The kinetic energy states that as the temperature of a substance increases, so do the average velocity of its particles and so the average kinetic energy.

Thas is why gases have a higher kinetic energy than liquids and liquids have a higher kinetic energy than solids.

The options A: H2O(s) changes to H2O(l) at 0°C and B: H2O(l) changes to H2O(s) at 0°C describe changes at constant temperature, so in them the  average kinetic energy does not change.

The option C: H2O(l) at 10°C changes to H2O(l) at 20°C, as said, is the right answer because it is a process in which the temperature is increasing, so the average kinetiic energy is also increasing.

The option D: H2O(l) at 20°C changes to H2O(l) at 10°C corresponds to a decrease of the kinetic energy, since the temperature is decreasing.

All the elements are arranged by melting points on the periodic table. in row they go from metals to gasses. in the row from sodium to argon, sodium is more reactive than the one on its right, magnesium.