PCAT: Chemistry Questions and Answers with 100% Complete Solutions | verified &updated 2024

PCAT: Chemistry Questions and Answers with 100% Complete Solutions | verified &updated 2024 Atomic number (z) - number of protons in the nucleus mass number (a) - number of protons plus the number of neutrons number of neutrons - mass number minus the atomic number for a neutral atom - mass number equals number of protons equals number of electrons elements - All the atoms of an element have the same atomic number isotopes - atoms of the same element that differ in mass number atomic weight - most elements have more than one naturally occurring isotope. The atomic weight of an element, properly atomic mass, is thus the weighted average of all the naturally occurring isotopes for that element Ions - atoms form ions by gaining or losing electrons cation - positive ion formed by the loss of one or more electrons anion - negative ion formed by the gain of one or more electrons Charge of IA elements - Na +1, K +1