Q: Which formula correctly calculates the mass number ($$M) of an $$atom?

$$M = \text{number of protons} + \text{number of neutrons}$$

Question 1

Which of the following statements correctly describes the difference between an element and a compound?

Accepted Answer

An element is a pure substance that cannot be broken down by chemical means, while a compound is a substance made of two or more elements chemically bonded together.

Question 2

A neutral atom of sodium (Na) has an atomic number of 11 and a mass number of 23. How many neutrons does it have?

Accepted Answer

12

Question 3

Which of the following best describes a cation?

Accepted Answer

An atom that has lost electrons and has a positive charge.

Question 4

Which formula correctly calculates the mass number ($$M) of an $$atom?

Accepted Answer

$$M = 	ext{number of protons} + 	ext{number of neutrons}$$

Question 5

Which of the following pairs of atoms is most likely to form a nonpolar covalent bond?

Accepted Answer

Oxygen and oxygen

Question 6

What is the maximum number of electrons that can occupy the second electron shell of an atom?

Accepted Answer

8

Question 7

Which of the following substances is a molecule but NOT a compound?

Accepted Answer

O$$_2$$

Question 8

Given the isotope carbon-14, which has an atomic number of 6, how many neutrons does it have?

Accepted Answer

8

Question 9

Which of the following best describes electronegativity?

Accepted Answer

The tendency of an atom to attract electrons in a chemical bond.

Question 10

Which of the following is true about ionic bonds?

Accepted Answer

They are formed when atoms transfer electrons from one to another.

Question 11

A chlorine atom (atomic number 17) gains one electron. What is the charge of the resulting ion?

Accepted Answer

-1

Question 12

Which of the following is an example of a compound that is NOT a molecule?

Accepted Answer

NaCl (sodium chloride)

Question 13

Which of the following statements about valence electrons is correct?

Accepted Answer

Valence electrons are the electrons in the outermost shell and are involved in chemical bonding.

Question 14

Which of the following best describes a polar covalent bond?

Accepted Answer

A bond where electrons are shared unequally between two different atoms.

Question 15

Which of the following elements is most likely to form an ionic bond with sodium (Na)?

Accepted Answer

Chlorine (Cl)

Question 16

Which of the following is true about isotopes?

Accepted Answer

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

Question 17

Which of the following is the correct electron configuration for a neutral carbon atom (atomic number 6)?

Accepted Answer

2 electrons in the first shell, 4 electrons in the second shell

Question 18

Which of the following substances is both a compound and a molecule?

Accepted Answer

H$$_2O ($$water)

Question 19

Which of the following best explains why noble gases are chemically inert?

Accepted Answer

They have a full valence shell of electrons.

Question 20

Which of the following is the correct formula for calculating the number of neutrons ($$N) in an $$atom?

Accepted Answer

$$N = 	ext{mass number} - 	ext{atomic number}$$

Atoms, Elements, and Chemical Bonding: Study Notes for General Biology

Guida di studio - Domande di pratica

Study guide - Flashcard