ussing the graduted cylinders below find the volume of the object. calculate the density of the mass is 78.42g

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.

particle   p is an electron and particle q is a neutron