2.2 Nuclides and Their Symbols

Question 1

Atoms of an element containing the same number of protons but different numbers of neutrons.

Answer 1

Isotopes

Question 2

A specific isotope of an element

Answer 2

Nuclide

Question 3

The number of protons in the nucleus of an atom.

Answer 3

Atomic Number

Question 4

The number of nucleons in the atoms.

Answer 4

Mass Number(A)

Question 5

A proton or neutron in a nucleus.

Answer 5

Nucleon

Question 6

Represents the average mass of the isotopes that compose the element, weighted according to the natural abundance of each isotope.

Answer 6

Atomic Mass

Question 7

Atoms of the same element that have the same number of protons in their nuclei but different numbers of neutrons.

Answer 7

Isotopes

Question 8

Any atom of any element that has a particular number of neutrons in the nucleus.

Answer 8

Nuclide

Question 9

Matter composed of atoms all having the same number of protons in their nuclei.

Answer 9

An Element

Question 10

Isotopes of a given element have the same _______, but different ________.

Answer 10

Same Atomic Number, but different Mass Numbers

Question 11

Atom that had gained or lost electron(s); charge atom

Answer 11

Ion

Question 12

Positive Ion

Answer 12

Cation

Question 13

Negative Ion

Answer 13

Anion

Question 14

An atom has the following chemical symbol: ¹¹⁴Cd

How many protons does this atom have?

How many neutrons does this atom have?

How many electrons, does this atom have?

Answer 14

48 Protons

66 Neutrons

48 Electrons

Question 15

How many neutrons are in the isotopes Sulfur-36?

Answer 15

20 Neutrons, since Sulfur-36 has an atomic mass of 36 and an atomic number of 16 we can calculate there are 20 neutrons. (36-16=20)

Question 16

How many neutrons are in Magnesium-27?

Answer 16

15 Neutrons, Since Magnesium has an atomic mass of 27 and an atomic number of 12 we can calculate that to be 15 Neutrons. (27-12=15)

Question 17

A neutral atom has 92 protons and a mass number of 238.

How many neutrons does this atom have?

How many electrons, does this atom have?

What is the symbol of this atom? Enter both the mass and the atomic number,

Answer 17

146 Neutrons since (238-92=146)

92 Electrons since it is a neutral atom and protons = electrons

²³⁸₉₂ U

Question 18

Astatine is a halogen with several isotopes that all have short half-lives. Which of the following combinations of mass number and neutrons are possible as isotopes of astatine?

Choose one or more:

A = 209, n = 124

A = 210, n = 125

A = 207, n = 122

A = 211, n = 127

A = 220, n = 134

Answer 18

A = 209, n = 124

A = 210, n = 125

A = 207, n = 122

This is calculated by deducting the Atomic Number 85 of Astatine from the Mass Number A.

Question 19

An ion has 19 Protons, 20 Neutrons, and 18 Electrons what is its symbol?

Answer 19

We can determine the element to be K because of the number of protons. We can also determine that the charge is +1 because there’s 19 protons and only 18 electrons. The Mass Number is calculated by adding the neutrons and protons to get 39.

³⁹ ₁₉ K⁺

Question 20

An ion has 12 protons, 12 neutrons and 10 electrons. What is its symbol?

Answer 20

We can determine this element to be Mg based of the number of protons. We can calculate the atomic mass as 24 since there are 12 protons and 12 neutrons. We can calculate the charge as a 2+.

^24​ ₁₂Mg²⁺