Hard periodic table quiz

Q: What does the hard periodic table quiz test?

Twenty questions on Cr and Cu configurations, ions that lose 4s first, VSEPR shapes, and lanthanide contraction. Five choices each.

Q: Can I print the hard quiz?

Yes. Print or download a blank paper from this page. After you submit, you can print or download a marked copy.

Q: Where are my answers stored?

Only in this browser, under a ptw.quiz.exceptions key. Leave unfinished and they wipe. Nothing is sent to a server.

Question 1

The measured ground state of chromium is:

Accepted Answer

[Ar] 3d⁵ 4s¹

Answer

[Ar] 3d⁴ 4s²

Answer

[Ar] 3d⁶

Answer

[Ar] 3d⁵ 4s²

Answer

[Ar] 3d³ 4s²

Question 2

The measured ground state of copper is:

Accepted Answer

[Ar] 3d¹⁰ 4s¹

Answer

[Ar] 3d⁹ 4s²

Answer

[Ar] 3d¹⁰ 4s²

Answer

[Ar] 3d⁸ 4s²

Answer

[Ar] 3d⁹ 4s¹

Question 3

Fe²⁺ in the gas phase is:

Accepted Answer

[Ar] 3d⁶

Answer

[Ar] 3d⁴ 4s²

Answer

[Ar] 3d⁶ 4s²

Answer

[Ar] 3d⁵ 4s¹

Answer

[Ar] 3d⁷

Question 4

The H–O–H angle in an isolated water molecule is about:

Accepted Answer

104.5°

Answer

109.5°

Answer

120°

Answer

90°

Answer

180°

Question 5

4s fills before 3d in K and Ca because:

Accepted Answer

n+ℓ is 4 for 4s and 5 for 3d, and 4s penetrates closer to the nucleus

Answer

3d has a larger n, so it always fills last

Answer

Pauli exclusion blocks 3d until 4s is full in every ion

Answer

4s has more radial nodes than 3d, so it is lower in every atom

Answer

the Madelung order is exact for transition-metal cations

Question 6

In a trigonal bipyramid, a lone pair occupies an equatorial site because:

Accepted Answer

axial positions have more 90° neighbors than equatorial ones

Answer

equatorial positions have more 90° neighbors than axial ones

Answer

lone pairs are smaller than bonding pairs, so they fit the short axial sites

Answer

180° axial room is always preferred for lone pairs

Answer

VSEPR does not distinguish axial from equatorial

Question 7

Hafnium’s atomic radius is close to zirconium’s mainly because of:

Accepted Answer

lanthanide contraction: poor 4f shielding raises Z_eff on Hf

Answer

actinide contraction

Answer

Hf having fewer electrons than Zr

Answer

they are isotopes of one element

Answer

5d orbitals expanding Hf far beyond Zr

Question 8

On the binding-energy-per-nucleon curve:

Accepted Answer

⁶²Ni has the highest B/A; ⁵⁶Fe has the lowest mass per nucleon

Answer

⁵⁶Fe has both the highest B/A and the lowest mass per nucleon

Answer

⁶²Ni holds both records

Answer

⁵⁸Fe is the peak of both curves

Answer

Cr-52 sits at the unique maximum

Question 9

Effective nuclear charge across a main-group period generally:

Accepted Answer

increases

Answer

decreases

Answer

stays constant because shielding keeps pace

Answer

drops only at the noble gas, then jumps

Answer

applies only in the d-block

Question 10

Hydrogen is not placed with the halogens, even though it is one electron short of He, because:

Accepted Answer

it has no p-core; H and F chemistry only partly overlap

Answer

it already has a p-subshell core like fluorine

Answer

it is a metal in every allotrope

Answer

IUPAC forbids hydrogen in group 1

Answer

it has two protons

Question 11

Hund’s rule for a subshell says:

Accepted Answer

maximize unpaired electrons with parallel spins before pairing

Answer

pair electrons in one orbital before occupying the next

Answer

fill 4s only after 3d is half full

Answer

invert spin every other electron

Answer

empty d orbitals before s orbitals in every atom

Question 12

The molecular shape of SF₄ is:

Accepted Answer

seesaw

Answer

tetrahedral

Answer

square planar

Answer

T-shaped

Answer

trigonal bipyramidal with five fluorines

Question 13

Scandium loses 4s electrons before 3d electrons because:

Accepted Answer

once 3d is occupied, 4s lies higher, so ions dump 4s first

Answer

4s is empty in the neutral atom

Answer

Madelung forbids 3d occupancy in any cation

Answer

3d electrons are farther from the nucleus than 4s in Sc²⁺

Answer

relativistic 4s contraction empties 3d instead

Question 14

Which list is the set of nuclear magic numbers?

Accepted Answer

2, 8, 20, 28, 50, 82, 126

Answer

2, 8, 18, 32, 50, 72

Answer

6, 10, 14, 18

Answer

8, 18, 36, 54, 86

Answer

1, 2, 3, 4, 5

Question 15

XeF₂ has:

Accepted Answer

trigonal-bipyramidal electron geometry and a linear molecule

Answer

linear electron geometry and a bent molecule

Answer

octahedral electron geometry and a linear molecule

Answer

tetrahedral electron geometry and a linear molecule

Answer

linear electron geometry and a linear molecule with no lone pairs

Question 16

Fluorine is more electronegative than chlorine, yet Cl has the more negative electron affinity because:

Accepted Answer

the extra electron on small F is crowded in 2p; Cl’s 3p has more room

Answer

fluorine is larger, so the extra electron is farther out

Answer

chlorine has a higher ionization energy than fluorine

Answer

fluorine already has a full 2p⁶ subshell

Answer

electron affinity and electronegativity are the same number

Question 17

Palladium’s ground-state configuration is:

Accepted Answer

[Kr] 4d¹⁰

Answer

[Kr] 4d⁸ 5s²

Answer

[Kr] 4d⁹ 5s¹

Answer

[Xe] 4d¹⁰

Answer

[Kr] 4d⁷ 5s²

Question 18

In diamond, each carbon is:

Accepted Answer

bonded to four others at tetrahedral angles

Answer

close-packed with 12 neighbors, as in FCC metals

Answer

in a BCC lattice with 8 neighbors

Answer

in a simple-cubic lattice

Answer

packed as HCP sheets of graphite

Question 19

Mercury is a liquid at room temperature mainly because:

Accepted Answer

relativistic 6s contraction weakens Hg–Hg bonding

Answer

it forms hydrogen bonds

Answer

it has no valence electrons

Answer

5d is empty, so packing is poor

Answer

its melting point is high and the liquid is supercooled

Question 20

The steric number of the oxygen atom in water is:

Accepted Answer

4

Answer

2

Answer

3

Answer

5

Answer

6

Hard periodic table quiz

Common questions

What does the hard periodic table quiz test?

Can I print the hard quiz?

Where are my answers stored?

Hard periodic table quiz

Common questions

What does the hard periodic table quiz test?

Can I print the hard quiz?

Where are my answers stored?