cation
A positively charged ion
anion
A negatively charged ion
why are ions important?
conduct electrical currents, muscles and nerves work bc of them, electrolytes
isotopes
atoms with different number of neutrons but same amount of protons and electrons
the number on the top left of an isotopic symbol is the
atomic mads
the number on the BOTTOM left of an isotopic symbol is the
number of protons/electrons
why are isotopes important for the human body?
using nuclear medicine, radioactive ones will show images of organs/body parts to diagnose/detect problems and also treat diseases
compound
made of more than one type of atom
molecule
made of more than one of the SAME atom
chemical reactions
making and breaking of bonds, forming new substances
ionic bonds
ions form electrons are lost or gained, then attract to each other to form a bond (ex. sodium chloride)
covalent bond
strongest bond, share electrons with an atom (ex. water)
nonpolar covalent
atoms shares electrons ewually
polar covalent
atoms share electrons unequally, making one part positive and the other part of the molecule negative
hydrogen bonds
the positive hydrogen of one molecule is attracted to a negative part of another polar molecule (ex. As-Ts , Cs-Gs)
van der waals forces
very short-lived, quick attracting between molecules holding them together, very weak (ex. geckos walking on walls)