atom
basic unit of matter
nucleus
center of the atom
holds the protons and neutrons
proton
positively charged particle in an atom
has mass
identifies atoms of a particular element
neutron
no charge
has mass
can lead to isotopes of an element
electrons
negatively charged particles in an atom
determine chemical behavior
valence electrons
the electrons in the outermost electron orbital
electron orbital (shell)
area outside of the nucleus in an atom that holds the electrons
atomic number
the number of protons in the nucleus of an atom
identifies an element
atomic mass
the number of protons and neutrons in the nucleus of an atom
ion
an atom that has an unequal number of protons and electrons
neutral atom
atom that has an equal number of protons and electrons
isotope
atoms of the same element that vary by mass
(difference is due to the number of neutrons)
covalent bond
bond formed between atoms that share electrons to fill their outermost electron shell
ionic bond
when one atom gives up an electron to another atom
Creates positive and negative ions that attract each other
polar covalent bond
covalent bond where the electrons are not shared equally and create slightly positive and negatively charged ends of the molecule
compound
substance composed of two or more different elements
molecule
substance composed of two atoms bonded together
acid
a substance that releases hydrogen ions into solution
pH 0-6.9
the lower the number the stronger it is
base
a substance that releases OH- ions into solution
pH 7.1-14
The higher the number the stronger it is
Buffer
substance that bind H+ ions, or release them to maintain homeostasis
pH
measure of the H+ ions and OH- ions in a solution
solvent
substance that dissolves another material
solute
substance that is dissolved in a solution
solution
one substance dissolved in another
concentration
- amount of solute dissolved in the solvent