Unit 2 Flashcards
Electrons are what cause
chemical reactions
electrons can be found in
different energy levels
each energy level corresponds to a
row on the periodic table
Horizontal rows of elements = X = X
period = no. of occupied e- shells
each energy level has what
sub-levels
electrons fill from
right to left
top to bottom
1S^1 what does each stand for
1= energy level S= sub level ^1= # of electron in the orbital
box diagrams
look at college or high school notes
valence electrons
how many does each group have
electrons in the highest energy level
g1= 1, g2=2, g3=3, g4=4, g5=5, g6=6, g7=7, g8=8
just as protons increase across the periodic table, what also increases
electrons
noble gases have how many valence electrons
8
the octet rule ?
atoms are most stable when they have 8 electrons in their valence shell
valence electrons are the
outermost, highest energy electrons
exceptions of the octet rule
H and He
noble gases all have
8 valence electrons
why are noble gases some of the last elements to be discovered
because they do not readily react
octet rule cont. – Atoms will
gain or lose electrons to have 8 valence electrons
atoms will gain or lose electrons to form
ions
what are the types of ions
cations and anions
what are cations
when a neutral atom has a loss of an electron
what are anions
when a neutral atom has a gain of an electron
Ca2+ has what biological important
1.5-2% of body mass, bones, teeth
necessary for blood clotting, digestion, formation of bones and teeth, actions of muscle(heart)
Mg2+ has what biological important
bones and teeth, intracellular activity
Fe2+ has what biological Important
neccessary for formation of hemoglobin and cytochromes, O2 transfer