They are called groups or family. Hope this helps
U-238 has 92 protons, 146 neutrons, and 92 electrons.
Rn-222 has 86 protons, 136 neutrons, and 86 electrons.
U-238 is Uranium 238 and Rn-222 is Radon 222.
B.) Instantaneous speed because the speedometer shows how fast you are going at that giving time .
Answer:
~Na+1 is already in the preferred form. Because of this, the second ionization energy of sodium is higher than normal. Mg+1 loses an electron to form s2 p6 .