Quiz 2 Flashcards
atoms
building blocks of matter
element
a pure substance made of only one kind of atom
trace element
an element indispensable for life but required in extremely minute amounts
atomic number
number of protons
mass number
the total number of protons and neutrons in the nucleus of an atom
atomic notation
a symbolic method for expressing the composition for an atomic nucleus
isotopes
atoms of the same element that have different numbers of neutrons
periodic table of elements
complete list of elements
atomic weight
average of the mass numbers of all isotopes
alkali metals
group 1
alkaline earth metals
group 2
halogens
group 17
inert/noble gases
grouop 18
transition metals
groups 3-12
ground state
most stable electron arrangement
excited state
atom has higher potential energy than it has in its ground state
electromagnetic radiation
the energy transferred through space by electromagnetic waves
quantum mechanics
series of energy levels (orbitals)
atomic orbitals
regions in space with a high probability of finding an electron
valence shell
outermost electron shell
valence electron
electrons on the outermost energy level of an atom
nuclear change
change in the nuclei of its atoms
nuclear radiation
the particles that are released from the nucleus during radioactive decay
radioisotopes
isotopes that have unstable nuclei and undergo radioactive decay
