Question 1

Which statement best describes the relationship between principal energy levels, subshells, and orbitals in the quantum model of the atom?

Accepted Answer

Principal energy levels are divided into subshells, and each subshell contains one or more orbitals.

Question 2

How many electrons can be accommodated in all the p orbitals of the second main shell?

Accepted Answer

6

Question 3

What is the ground state electron configuration for oxygen (atomic number 8)?

Accepted Answer

$$1s^2$$\ $$2s^2$$\ $$2p^4$$

Question 4

Which element has the electron configuration $$1s^2$$\ $$2s^2$$\ $$2p^6$$\ $$3s^1$$?

Accepted Answer

Sodium

Question 5

How many valence electrons does chlorine (atomic number 17) have?

Accepted Answer

7

Question 6

Which of the following best explains why potassium (K, atomic number 19) fills the 4s orbital before the 3d orbital?

Accepted Answer

The 4s orbital has a lower energy than the 3d orbital.

Question 7

A sample contains 10 g of $$Fe_2O_3 ($$rust). How many grams of iron (Fe) are present in the sample? (Atomic masses: Fe = 55.845, O = 15.999)

Accepted Answer

6.99 g

Question 8

Which of the following is the correct electron configuration for chlorine (atomic number 17)?

Accepted Answer

$$1s^2$$\ $$2s^2$$\ $$2p^6$$\ $$3s^2$$\ $$3p^5$$

Question 9

Which analogy best describes the relationship between shells, subshells, orbitals, and electrons in an atom?

Accepted Answer

Shells are like floors in a hotel, subshells are sets of identical rooms, orbitals are rooms, and electrons are guests.

Question 10

Which of the following elements is a non-metal according to the periodic table classification?

Accepted Answer

Oxygen (O)

Question 11

How many electrons can be accommodated in all the d orbitals of a main shell?

Accepted Answer

10

Question 12

Which of the following is the correct order of filling for the first four subshells according to the Aufbau principle?

Accepted Answer

$$1s \rightarrow 2s \rightarrow 2p \rightarrow 3s$$

Question 13

Which group on the periodic table contains elements with a full outer shell of electrons?

Accepted Answer

Noble gases

Question 14

What is the maximum number of electrons that can occupy the 3p subshell?

Accepted Answer

6

Question 15

Which of the following statements about valence electrons is correct?

Accepted Answer

Valence electrons are responsible for chemical bonding and reactivity.

Question 16

Carbon (atomic number 6) has which ground state electron configuration?

Accepted Answer

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

Question 17

Which of the following elements is classified as a transition metal?

Accepted Answer

Iron (Fe)

Question 18

If an atom has the electron configuration $$1s^2$$\ $$2s^2$$\ $$2p^6$$\ $$3s^2$$\ $$3p^6$$\ $$4s^2$$, what is its atomic number?

Accepted Answer

20

Question 19

Which of the following is a correct statement about the periodic table organization?

Accepted Answer

Elements are organized by increasing atomic number.

Question 20

Which of the following best describes the difference between metals and non-metals on the periodic table?

Accepted Answer

Metals tend to lose electrons in reactions, while non-metals tend to gain electrons.

Orbitals and the Periodic Table: Electron Arrangement and Chemical Properties

Study Guide - Practice Questions