Question 1

Which of the following statements best describes the Aufbau Principle in electron configuration?

Accepted Answer

Electrons fill orbitals in order of increasing energy, starting from the lowest energy orbital.

Question 2

What is the condensed electron configuration for phosphorus (Z = 15)?

Accepted Answer

[Ne] $$3s^2$$ $$3p^3$$

Question 3

Which element is the most electronegative among the following Group 7A elements?

Accepted Answer

Cl

Question 4

According to the octet rule, how many valence electrons does oxygen have in a water molecule (H2O)?

Accepted Answer

8 octet electrons: 6 valence and 2 shared electrons

Question 5

What is the formal charge on the central carbon atom in the thiocyanate ion (NCS^-)? (N is Group 5A, C is Group 4A, S is Group 6A)

Accepted Answer

0

Question 6

When drawing Lewis Dot Structures, which element should never be placed in the center of the molecule?

Accepted Answer

Hydrogen

Question 7

Which of the following statements about resonance structures is correct?

Accepted Answer

Resonance structures differ only in the placement of electrons, not atoms.

Question 8

What is the hybridization of the central atom in HCN (hydrogen cyanide)?

Accepted Answer

sp

Question 9

Which of the following molecules is polar?

Accepted Answer

NH3

Question 10

Which functional group is present in the following structure: CH3COOH?

Accepted Answer

Carboxylic acid

Question 11

Which of the following is a hydrocarbon?

Accepted Answer

CH3CH2CH3

Question 12

A neutral atom of carbon-14 ($$^{14}C) $$has how many protons, neutrons, and electrons?

Accepted Answer

6 protons, 8 neutrons, 6 electrons

Question 13

Which principle is being violated if two electrons in the same orbital have the same spin?

Accepted Answer

Pauli Exclusion Principle

Question 14

Which of the following best describes a resonance hybrid?

Accepted Answer

A composite of all major resonance structures.

Question 15

How many electron groups are around the central atom in a molecule with tetrahedral geometry?

Accepted Answer

4

Question 16

Which of the following molecules is nonpolar due to its perfect shape?

Accepted Answer

CO2

Question 17

What is the formal charge on the oxygen atom in the nitrate ion ($$NO_3$$^-$$) if it is drawn with a single bond to nitrogen and three lone pairs?

Accepted Answer

-1

Question 18

Which of the following best describes the difference between isotopes of hydrogen?

Accepted Answer

They have the same number of protons but different numbers of neutrons.

Question 19

Which of the following is the correct order of increasing electronegativity for the elements Na, Cl, and F?

Accepted Answer

Na \u003c Cl \u003c F

Question 20

A molecule has three electron groups and no lone pairs on the central atom. What is its electron geometry and hybridization?

Accepted Answer

Trigonal planar, sp2

GOB Chemistry Study Notes: Atomic Structure, Bonding, and Organic Chemistry Fundamentals

Study Guide - Practice Questions