I.1. 5 points
Minimum energy required to remove an electron from an atom in the gas phase.
OR
Energy of the reaction A(g) → A+(g) + eGas phase forgotten: -2 pts
I.2. 6 points
Along the period, Z increases, but additional screening is small (valence electrons) (1pt), therefore
Zeff increases (2 pts). Radius decreases (2 pts), ionization energy increases (1pt).
Relative proximity to close shell explanation gets 2 pts.
I.3. 6 points
Version A:
Electronic configurations of Be (1s22s2) and B (1s22s22p1) (2 pts)
Easier to remove electron from B to form closed-shell (2 pts) than from Be to form open shell (2pt)
Version B:
Electronic configurations of N (1s22s22p3) and O (1s22s22p4) (2 pts)
Easier to remove electron from O to form half-filled subshell (2 pts) than from N to destroy that
half-filled shell (2 pts)
II.1. 6 points
l = 0 and ml = 0 or l = 1 and ml = -1, 0 or 1
l values: 2 pts
l and ml values, not grouped: 3 pts
II.2 8 points
l = 0 2s
l = 1 2px, 2py, 2pz
drawing
drawings
Missing/wrong orbital: -3 pts
Missing/wrong name or l value: -1 pt
II.3. 5 points
Version A:
c
−7
λ= ν =6.56×10 m=656 nm , red.
Version B:
c
−7
λ= ν =4.86×10 m=486 nm , blue.
Formula 2 pts, result 2 pts, color 1 pt.
Wrong number of significant figures -1pt.
II.4. 7 points
Rydberg equation
Version A:
ni = 3
Version B:
ni = 4
1
1
1
, (3 pts) nf = 2.
λ =R∞ n 2 − n 2
f
i
(
)
ni not given as integer : -2 pts
III.1. 5 points
m
=7.26×103 kg.m−3
2
d
π
t
2
m
3
−3
Version B: Density ρ=
=6.67×10 kg.m
2
d
π
t
2
Version A: Density ρ=
()
()
Formula: 2 pts (OK if written with r instead of d/2)
Wrong significant figures: -1 pt
III.2. 8 points
m=mCu + mNi=(1−x Ni) n M Cu + x Ni n M Ni
m
n=
x Ni M Ni +(1−x Cu ) M Cu
mNi=x Ni nM Ni
and
mCu =m−mNi=(1−x Ni )nM Cu
p= pNi mNi + pCu m Cu
Version A:
−2
n=3.593×10 mol
mNi=1.249 g and mCu =3.751 g
p=3.36 cents
Version B:
n=8.031×10−2 mol
mNi=0.189 g and mCu =2.079 g
p=1.27 cents
Introduction of the total number of atoms (in moles or atoms): 2 pts
Right formula of that number: 2 pts
Right formula for the masses: 1 pt
Right formula for the price: 2 pt
Wrong number of significant figures: -1 pt
III.3. 6 points
Version A: 63Cu has 29 e-, 29 p+, 63-29=34 n.
Version B: 58Cu has 28 e-, 28 p+, 58-28=30 n.
2 pts for e-, 2 pts for p+, 2 pts for n
Wrong atom: 0 points
1 pt if A-Z formula given for n with wrong result
III.4. 6 points
M =x 1 M 1 +x 2 M 2
Version A: 63.55 g.mol−1=6.355×10−2 kg.mol−1
Version B: 58.69 g.mol−1=5.869×10−2 kg.mol−1
Formula: 2 pts
Right result, wrong unit: -2 pts
Wrong number of significant figures: -1 pt
III.5. 8 points
Pauli (1 pt), no two atoms with same quantum numbers or no more than two electrons per orbital
(1 pt for either one)
Aufbau (1 pt), increasing energy (1pt), increasing n+l (1 pt), then increasing n (1pt)
Hund (1 pt), maximum total spin or maximum number of parallel spins (1 pt for either one)
III.6. 6 points
Ni :1 s 2 2 s2 2 p6 3 s 2 3 p6 4 s 2 3 d 8=[Ar] 4 s2 3 d 8
3 points each
III.7. 4 points
10 valence electrons (2 points) in 4s and 3d subshells (2 pts).
III.8. 5 points
□
□□□□□
4s
3d
↑↓
↑↓ ↑↓ ↑↓ ↑ ↑
Spin = 1
1 pts
2 pts
2 pts
4s forgotten, or all orbitals represented: -1
III.9. 4 points
Ni 2+ :[Ar] 3 d 8
If complete representation (not noble core): 2 pts
III.10. 5 points
Version A: chemical properties = b, d
Version B: physical properties = c, d, e
+1 per correct, -1 per wrong
III.11. 5 points
Version A: T a=293 K <mp <T b=1729 K < bp<T c =3023 K so Ta↔ ρ3 , Tb↔ ρ2 , Tc↔ ρ1 because
solid more dense than liquid and liquid more than gas.
Version B: 20 °C=293 K< mp<1086 °C=1729 K < bp<2620 °C=3023 K so 20°C↔ ρ3 ,
1086°C↔ ρ2 , 2620°C↔ ρ1 because solid more dense than liquid and liquid more than gas.
Conversion to kelvins: 1 pt
Density solid-liquid-gas: 2 pts
Correlation: 2 pts
Version B: error in text (“nickel” should have been “copper”) adressed reasonably +1 pt.