Water is the only substances on earth that occur naturally as a solid, liquid, and gas. Water can be found in 3. A. states of matter
B. Shows on television
C. Elements on the periodic table
D. Human body systems

h let me think

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.

i just learnt this recently but i need to look through my notes again