gchem 1 Flashcards
What does Z mean?
atomic number
What does A mean?
mass number
Why are anions larger than cations?
anions are bigger because they have gained electrons which repel each other and take up more space
metals are __ atoms with __ held electrons
larger, loosely
non-metals are __ atoms with __ held electrons
smaller, tightly
Why are larger atoms better at stabilizing charges?
form weaker pi binds because of decrease in overlapping p orbitals
What is the difference between electron affinity and electronegativity?
electronegativity - propensity of atom attracting an electron
electron affinity - amount of energy liberated when a molecule or neutral atom acquires an electron from outside
What is the first quantum number?
n - shell
what is the second quantum number?
l - subshell or orbital
What is the 3rd quantum number?
ml - orbital orientation , value from -L to L
What is the 4th quantum number?
Ms- spin (+ or -)
How many electrons in the s, p, d, f orbital?
2, 6, 10, 14
What are the Heisenberg Uncertainty and Pauli Exclusion principles?
Pauli Exclusion principle - no two electrons can all 4 quantum numbers the same
Heisenberg Uncertainty principle- more known ab electron position, the less we know about its momentum
What is the formula for the energy of a photon?
E = hf
h- planks constant
f- frequency
What is the formula for the energy of a photon?
E= hc/lambda
what is radioactive decay?
process by which unstable atoms change their chemical composition over time.
What is alpha decay?
loss of one He nucleus, which has a mass of 4 and atomic number of 2
What is beta decay?
neutron is changed into a proton - ejection of an electron
What is electron capture ?
proton is changed into neutron - via capture of electron
What is positron emission?
proton is changed into a neutron- expulsion of positron
What is gamma emission?
gamma rays are usually emitted as a byproduct of the types of decay outlined
What is half-life?
the amount of time required for exactly one-half of the mass of that substance to disappear due to radioactive decay
___ bonding orbitals are higher in energy than __ orbitals
anti, bonding
What’s the difference between covalent and ionic bonds?
covalent - 2 nonmetals are bonded (sharing of electrons)
ionic - metal and nonmetal (electrostatic attraction)
What makes a good electrolyte?
when compounds dissociate completely in water (ionic compounds are always good electrolytes)
Which two elements in the periodic table, if bonded, would create a bond with the maximum possible ionic character?
Francium fluoride