$$2n^2 = 2$$ \times $$3^2 = 18$

Question 1

Which of the following statements best explains why elements are considered the building blocks of matter?

Accepted Answer

Elements are substances that cannot be broken down into simpler substances by chemical means.

Question 2

Which of the following is the correct way to write the symbol for the element magnesium?

Accepted Answer

Mg

Question 3

A neutral atom of calcium has an atomic number of 20 and a mass number of 40. How many neutrons does it have?

Accepted Answer

$$40 - 20 = 20$$ neutrons

Question 4

Which of the following best describes the location and properties of metalloids on the periodic table?

Accepted Answer

Metalloids are found along the zig-zag line between metals and nonmetals and have properties of both.

Question 5

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes of an element have the same number of protons but different numbers of neutrons.

Question 6

Which equation correctly shows how to calculate the maximum number of electrons in the third energy level (n = 3)?

Accepted Answer

$$2n^2 = 2$$ 	imes $$3^2 = 18$

Question 7

Which of the following best describes what happens when an electron in an atom absorbs energy?

Accepted Answer

The electron moves to a higher energy level, entering an excited state.

Question 8

A neutral atom of oxygen has 8 electrons. What is its electron configuration?

Accepted Answer

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

Question 9

Which of the following is the correct condensed electron configuration for sodium (Na, atomic number 11)?

Accepted Answer

$$[Ne]\ 3s^1$

Question 10

Which statement about valence electrons is correct?

Accepted Answer

Valence electrons are the electrons in the outermost energy level and determine chemical properties.

Question 11

Which of the following best describes the Pauli Exclusion Principle?

Accepted Answer

No two electrons in the same atom can have the same set of four quantum numbers.

Question 12

A neutral atom of carbon has 6 protons and 6 electrons. Which Lewis dot structure correctly represents carbon?

Accepted Answer

C with four dots around it (one on each side)

Question 13

Which property is NOT characteristic of metals?

Accepted Answer

Brittle

Question 14

If an atom has 17 protons, 18 neutrons, and 17 electrons, what is its mass number?

Accepted Answer

$$17 + 18 = 35$$

Question 15

Which of the following statements about the periodic table is correct?

Accepted Answer

Elements in the same group have similar chemical properties.

Question 16

Which of the following is true about the electron cloud in an atom?

Accepted Answer

It is the region where electrons are likely to be found surrounding the nucleus.

Question 17

A neutral atom of fluorine has 9 electrons. How many electrons are in its outermost shell?

Accepted Answer

7

Question 18

Which rule states that electrons fill orbitals singly before pairing up?

Accepted Answer

Hund's Rule

Question 19

Which of the following best explains why most of an atom’s mass is located in the nucleus?

Accepted Answer

Protons and neutrons, which are much heavier than electrons, are found in the nucleus.

Question 20

Which of the following is the correct electron configuration for a neutral atom of neon (atomic number 10)?

Accepted Answer

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

Atoms and Elements: Chapter 4 Study Guide

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