The elements of same group are placed in same group as they have similar properties. So Calcium is the element which resembles Mangesium.
Calcium and Magnesium both are alkaline earth metals.
They have similar properties as they have similar outer or valence shell electronic configuration
The general electronic configuration of alkaline earht metal is ns2
The electronic configuration of Mg [atomic number 12] and Ca [atomic number 20] are
and
respectively.
Explanation:
When water is frozen then it is known as ice and its state is solid. So, its molecules will be held closer to each other as they are held by strong intermolecular forces of attraction.
As a result, its temperature will be minimum as its molecules have least kinetic energy.
It is known that kinetic energy of a substance is directly proportional to temperature.
As, K.E =
where K.E = kinetic energy
T = temperature
k = boltzmann constant
When solid changes into liquid state then it means molecules of a substance has gained kinetic energy due to which there occurs more collisions between the molecules.
Hence, temperature of substance also increases.
Whereas when liquid state of a substance changes intro vapor state then it means that more kinetic energy has gained by the molecules due to which there will be much more collisions between the molecules.
Hence, temperature will be maximum in vapor state.