If you mix 100 milliliters of 10 degrees celsius of water and 100 milliliters of 90 degrees celsius of water what will be your final temperature of the mixture

Final temperature of the mixture is 50°C

Explanation:

This is a typical calorimetry problem,  where the heat yielded by a compound is immediately won by another.

Water at  90°C raise the temperature of water at 10°

Density of water = 1g/mL

Mass of water = 100 g, because the volume is 100mL

If the two pieces of water are in a calorimeter where heat is not released or gained, the sum of both heats is 0

4.18 J/g°C . 100 g ( T°final - 90°C) +  4.18 J/g°C . 100 g ( T°final - 10°C) = 0

418 J/°C T°final - 37620 J + 418 J/°C T°final - 4180J = 0

836 J/°C T°final - 37620J - 4180J = 0

836 J/°C T°final = 41800J

T°final =  41800J / 836 °C/J = 50°C

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.