3. A 50.0 gram piece of iron (specific heat = 0.450 J/g-C°) is heated to 100. C° in boiling water and then dropped into 80.0 grams of water at
22.0 C° Calculate the equilibrium temperature.

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.

the objects have the same charge.