$$n=4,\ l=0,\ m_l=0,\ m_s=+\frac{1}{2}\ \text{or}\ -\frac{1}{2}$$

Question 1

Which of the following best explains why elements in the same group of the periodic table have similar chemical properties?

Accepted Answer

They have the same number of valence electrons.

Question 2

Which element is classified as a transition metal?

Accepted Answer

Cr

Question 3

According to Coulomb’s Law, what happens to the potential energy of two oppositely charged particles as they get closer together?

Accepted Answer

The potential energy decreases.

Question 4

Which of the following electron configurations represents a violation of the Pauli Exclusion Principle?

Accepted Answer

$$1s^2$$\ $$2s^2$$\ $$2p^7$$

Question 5

Which set of quantum numbers is possible for an electron in a 4s orbital?

Accepted Answer

$$n=4,\ l=0,\ m_l=0,\ m_s=+\frac{1}{2}\ 	ext{or}\ -\frac{1}{2}$$

Question 6

Which of the following elements has the greatest effective nuclear charge experienced by its valence electrons?

Accepted Answer

S

Question 7

Which of the following ions is isoelectronic with Argon ($$Ar$$)?

Accepted Answer

$$K^+$$

Question 8

Which of the following statements about atomic radii is correct?

Accepted Answer

Atomic radius increases down a group and decreases across a period.

Question 9

Which of the following elements would you expect to have the highest first ionization energy?

Accepted Answer

S

Question 10

A main-group element has an outer electron configuration of $$ns^2np^4$. What charge is likely for an ion of this element?

Accepted Answer

$$2-$$

Question 11

Which of the following best explains why sodium commonly forms a $$1+$$ ion and not a $$2+$$ ion?

Accepted Answer

Sodium has only one valence electron that is easily removed; removing a second electron would be more difficult because it would be a core electron.

Question 12

Which of the following ions is paramagnetic?

Accepted Answer

$$Fe^{3+}$$

Question 13

Which of the following elements has an anomalous electron configuration due to a half-filled or fully filled d sublevel?

Accepted Answer

Cr

Question 14

Which of the following statements about electron affinity is correct?

Accepted Answer

Halogens have the highest (most negative) electron affinities in a period.

Question 15

Which of the following best describes the trend in metallic character in the periodic table?

Accepted Answer

Metallic character increases down a group and decreases across a period.

Question 16

Which of the following is the correct electron configuration for a $$Br$$ atom?

Accepted Answer

$$1s^2$$\ $$2s^2$$\ $$2p^6$$\ $$3s^2$$\ $$3p^6$$\ $$4s^2$$\ $$3d^{10}$$\ $$4p^5$$

Question 17

Which of the following pairs are isoelectronic?

Accepted Answer

$$Na^{+}$$\ and\ Ne$

Question 18

Which of the following best describes Hund’s Rule?

Accepted Answer

Electrons occupy degenerate orbitals singly with parallel spins before pairing.

Question 19

Which of the following statements about the size of ions is correct?

Accepted Answer

Cations are smaller and anions are larger than their parent atoms.

Question 20

Which of the following elements would have a large jump between its third and fourth ionization energies?

Accepted Answer

Be

Periodic Properties of the Elements: Structure, Electron Configuration, and Trends

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