Which ion is the only negative ion present in an aqueous solution of an arrhenius base?
(1) hydride ion (3) hydronium ion
(2) hydrogen ion (4) hydroxide ion

zfoods? ok, pressure is used to keep the heat inside and to keep the food perfect.

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.