Answer:

Explanation:
At
, the heat of vaporization of water is given by:

The water here condenses and gives off heat given by the product between its mass and the heat of vaporization:

The block of aluminum absorbs heat given by the product of its specific heat capacity, mass and the change in temperature:

According to the law of energy conservation, the heat lost is equal to the heat gained:
or:

Rearrange for the final temperature:

We obtain:

Then:

Answer:
Explanation:
A is Magnesium, B is Aluminium both are adjacent element and lie in third period.
Magnesium with atomic number of 12 consist two s electrons in it's valence shell in ground state whereas, Aluminium which has atomic number of 13 consist three electrons in it's valence shell in the ground state out of which two are s electrons and only one p electron.
The chemical equation without coefficients is:
Ca + CO2 + O2 --------> Ca CO3
You can balance that equation by trial an error.
This is the chemical equation balanced:
2Ca + 2CO2 + O2 --------> 2Ca CO3
Count the atoms on each side to check the balance
Atom Left side right side
Ca 2 2
C 2 2
O 2*2 + 2 = 6 2*3 = 6
Then those are the coefficients:
a0 = 2
a1 = 2
a2 = 1
a3 = 2