Chem Test 2
n=1 how many orbitals? how many electrons?
1 orbital 2 electrons
The number of orbitals in a s subshell is __________.
1 orbitals
A possible set of quantum numbers for the last electron added to complete an atom of gallium (Ga) in its ground state is _________.
1. Find # of electrons. --- 31 2. Write electron configuration [Ar]4s^2 3d^10 4p^1 3. n=4 l=1 ml= -1,0,1 ms= -1/2 or 1/2
Physical Interpretation of Wavefunction (Ψ)
1. Wavefunctions are orbitals 2. Wavefunction squared (Ψ^2) is the probability of finding an electron in some region of space.
What is Hund's Rule?
1. the most stable arrangement of electrons in orbitals of equal energy is the one in which the number of electrons with parallel spin are maximized 2. spins remain same prior to adding a second electron to any state 3. orbitals will fill in parallel first
The maximum number of electrons that can occupy an energy level described by the principal quantum number, n, is given by ____________
2n^2 [n^2 gives number of electrons and there are 2 electrons in each orbital]
How many orbitals are there in the n = 4 level of the H-atom?
2n^2 = number of electrons n^2 = number of orbitals 4^2 = 16 orbitals
The number of orbitals in a p subshell is _____________.
3 orbitals
The number of orbitals in a d subshell is _____________.
5 orbitals
The number of orbitals in a f subshell is ___________.
7 orbitals
n=3 how many orbitals? how many electrons?
9 orbitals 18 electrons
Give the electron configuration of the following elements: Be, N, F, Al, S, Sc, Cr, Cu, and Re
Be [He] 2s2 N [He] 2s2 2p3 F [He] 2s2 2p5 Al [Ne] 3s2 3p1 S [Ne] 3s2 3p4 Sc [Ar] 4s2 3d1 Cr [Ar] 4s1 3d5 Cu [Ar] 4s1 3d10 Re [Xe] 6s2 4f14 5d5
Give the electron configuration of the following ions: C2+, Ti3+, Na1-, and S2-
C2+ [He] 2s2 Ti3+ [Ar] 3d1 Na1- [Ne] 3s2 S2- [Ne] 3s2 3p6.
Atomic orbitals that have the same amount of energy are
Degenerate (same n = same energy = degenerate)
How many orbitals are allowed in a subshell if the angular momentum quantum number for electrons in that subshell is 3?
GIVEN: l=3 so... ml = -3,-2,-1,0,1,2,3 7 orbitals allowed in the subshell . Also, l=3 is an F orbital which has 14 electrons and 7 orbitals.
Plot the RDP for 3s, 3p, 3d, orbitals and label them.
Label the nodes (they will all be radial nodes(???????)
State the Pauli Exclusion Principle
No 2 electrons can have the same 4 quantum numbers
What is the maximum number of electrons in an atom that can have the following set of quantum numbers? n = 4 l = 3 ml = -2ms = +1/2
The Pauli Exclusion principle states that no 2 electrons can have the same 4 quantum numbers so the answer is 1.
Why are s orbitals spherical?
The angular part of the wavefunction is constant and therefore the orbital only depends on a radial part (distance from nucleus in 3 directions).
Draw the P orbitals and name them.
There are 3 p orbitals. px, py, pz. Only 1 lobe should be shaded
Draw the D orbitals and name them.
There are 5 d orbitals. dxy dyz dxz dx^2-y^2 dz^2
What four elements in the fourth period, n = 4, have two, and only two, unpaired electrons?
Ti, Ni, Ge, Se
Electrons in an orbital with l = 3 are in which orbital?
f orbital
Angular Quantum Number
l l= 0,1,2,3....(n-1) describes subshell / SHAPE OF ORBITAL ***l=0 . s orbital l=1 . p orbital l=2 . d orbital l=3 . f orbital
Transition metals
lose S first are pretty much the entire D block
Magnetic Spin Quantum Number
m (sub s) -1/2 or 1/2 designates which way the electron spins.
Magnetic Quantum Number
m(sub l) -l ... 0 ... l designates orientation of orbital (orientation on xyz axis) number of ml options is number of orbitals in a subshell
Principle Quantum Number
n n=1,2,3...infinity determines binding energy / energy level of orbital
How do you find the number of orbitals?
n squared (n^2)
What is the correct set of quantum numbers for an electron in a 3p orbital?
n=3 l=1 ml=-1,0,1 ms=-1/2 or 1/2
What is the correct set of quantum numbers for an electron in the 3d orbital?
n=3 (energy level) l=2 (because d orbital) m(sub l)= -2,-1,0,1,2 m(sub s) = -1/2 or 1/2
What is the correct set of quantum numbers for an electron in a 5f orbital?
n=5 l=3 m(sub l) = -3,-2,-1,0,1,2,3 m(sub s) =-1/2 or 1/2
The energy of an electron in a H atom is determined by which quantum numbers?
only N - the principal quantum number because [ e = (-z^2Rh)/n^2 ] only depends on n.
Degenerate means ________
same energy (in an atomic orbital) it also means same n
What is effective nuclear charge?
the attractive force between the nucleus and electrons. This changes depending on the orbital because electrons in closer orbitals shield the nucleus's force from other electrons. S shields the best.
