Vocabulary Flashcards
isotopes
atoms with different number of neutrons
ions
lost or gained electrons (positive = cations, negative = anions)
atomic number
equal to the number of protons, defines the element
atomic mass
equal to the number of protons plus the number of neutrons
beta radiation
medium radiation, an electron (^0 -1e) is ejected and a neutron becomes a proton
alpha radiation
weakest radiation, a helium nucleus ( ^4 2He ) is emitted
energy levels
ring on a Bohr model
gamma radiation
strongest radiation, a high energy photon ( ^0 0Y) is emitted
orbitals
region of space where you are most likely to find an electron
valence electrons
electrons on the outermost ring
hund’s rule
electrons spread out in an orbital type before they pair up
aufbau principle
electrons occupy lower energy levels first
pauli exclusion principle
electrons in an orbital must have opposite spins
metals
left side of PT, luster, malleable, ductile, good conductors
metalloids
along stair step line of PT, mixed properties
non metals
top right of PT, brittle, various colors, poor conductors
group vs period
Group- column on PT, have similar properties and same # valence electrons
Period - row on PT, have same number of energy levels and shielding electrons
alkali metal
group 1, very reactive metals, react with water
akaline earth metals
group 2, reactive metals
transition metals
groups 3-12, less reactive metals, charges can vary
halogens
group 17, very reactive nonmetals
noble gases
group 18, inert (nonreactive) nonmetals
atomic radius
refers to size of an atom, francium is biggest
ionization energy
energy required to remove an electron, helium has the highest
electronegativity
ability of an atom to attract an electron, fluorine has the highest
ionic bond
between metal and nonmetal, high melting points, conduct electricity
covalent bond
between nonmetals, low melting points, do not conduct electricity
empirical formula
simplest formula, show ratio of elements
molecular formula
shows what’s actually in the molecule
polar
polar is an unequal sharing of electrons (electrons on the central
atom)
nonpolar
nonpolar is an equal sharing of electrons
accuracy
accuracy refers to how correct you are
precision
precision refers to how close together your
measurements are
Ph
-turn litmus paper red
potential of hydrogen
POh
-turn litmus paper blue
potential of hydroxide
Polar
non soluble
non polar
soluble