Ch. 6 & 7 Atom & Periodic Trends Test Key
Dmitriy Samusenko and Karen Wong
1. A green light is shone onto a green solution – would the absorbance be zero or infinity (is %
transmission 100% or 0%, respectively)? Justify/ rationalize your answer.
Green solution if there is transmission of green light: Abs= -log%T ← 100%
Abs∼ 0
2. If a photon of light have a wavelength of 275 nm, what is its energy?
𝑐
i) λf=c → f=
𝑐
→
3 ∙ 10 8 𝑐/𝑐 10 9 𝑐𝑐
275 𝑐𝑐
∙
= 1.091× 1015 𝑐−1
1𝑐
15
ii) Energy=hf →6.63∙ 10−34 𝑐(1.091× 10 𝑐−1)
= 7.23∙ 10−19 𝑐
3. Sketch the orbital diagram for silicon; many not use Nobel gas “short-cut,” then identify its
valence and core electrons.
↑↓
↑↓
1s
{
↑↓
↑↓
↑↓
↑↓
↑
2s
2p
𝑐𝑐𝑐𝑐 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐
↑
3s
}
{
3p
valence electrons
}
4. Which atom, carbon or nitrogen, has the larger atomic size? Justify/ rationalize your choice.
Carbon has lower Z and +s compared to nitrogen. There is lower 𝑐𝑐𝑐𝑐 and lower 𝑐𝑐𝑐𝑐 which
increases the size. Carbon’s electrons are further away from the nucleus so less attraction and
more shielding.
5. Based on the reading assignment, describe the periodic table trend in the ionization energy in a
row of the transition metals. Justify/rationalize this trend.
Left to right: greater Z and more shielding → ±𝑐𝑐𝑐𝑐 → ± 𝑐𝑐𝑐𝑐 → ±ionization energy
6. Based on the reading assignment, which molecule, LiF or NaF, has the larger lattice energy;
Justify/ rationalize answer.
Li has less electron shell: smaller size →greater 𝑐𝑐𝑐𝑐 →greater lattice energy
Old topic: IN regards to ATP hydrolysis shown below, [10 points]
a. In the above diagram, identify where/when energy is consumed versus generated. Is there
a net consumption or generation of energy in the above reaction?
- Energy is consumed when it breaks bonds. Energy is generated when it forms bonds.
There is a generation of energy.
b. Describe the concept of a “coupled reaction” in the context of the muscle contraction (and
ATP hydrolysis)
They both happen together
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5) Ch. 6 & 7(Partners: Ralph, Dmitriy & Karen) : Atom & Periodic Trends
1. A green light is shone onto a green solution – would the absorbance be zero or
infinity(or % transmission is 100% or 0% respectively)? Justify/rationalize your answer.
Green solution due to transmit green light; Absorbance = -log%T
% = 100 so Absorbance = 0
2. If a photon of light have a wavelength of 275 nm, what is its energy?
i)
λf =c  f = c/λ = 3x10^8m/s /(275 nm)(10^9nm)/(1m) = 1.091x10^15 s-1
ii)
E=hf = 6.63x10^-34 J(1.091x10^15 s-1 )
= 7.23x10^-19 J
3. Sketch the orbital diagram for silicon; may not use Nobel gas “short-cut”, then identify
its valence and core electrons
[ core electrons…………..]
[valence electrons….]
4. Which atom, carbon or nitrogen, has the larger atomic size? Justify/rationalize your
choice.
Carbon compared to nitrogen
Small z & +/- s  small Zeff  small Fatt  big size
5. Based on the reading assignment, describe the periodic trend in the ionization energy in a
row of the transition metals; rationalize/justify this trend.
L R : big z & big s  +/- Zeff  +/- Fatt  +/- IE
6. Based on the reading assignment, which molecule, LiF or NaF, has the larger lattice
energy; justify/rationalize your answer.
Li has less electron shell : small size  big Fatt  big lattice energy
Old Topic
7. In regards to ATDP hydrolysis shown below,
a. In the above diagram, identify where/ when energy is consumed versus generated. Is
there a net consumption or generation of energy in the above reaction?
Generation of energy means forming bonds. Consuming energy means breaking
bonds. There’s a net generation of energy in the above reaction.
b. Describe the concept of a “coupled reaction” in the context of muscle contraction(and
ATP hydrolysis).
Both happen together.