isotopes and atomic mass

Question 1

What does ‘iso’ refer to in chemistry?

Answer 1

Iso refers to isotopes, which are variants of a chemical element that have the same number of protons but different numbers of neutrons.

Question 2

True or False: Isotopes of an element have different atomic masses.

Answer 2

True

Question 3

Fill in the blank: The atomic mass of an element is the weighted average of the masses of its __________.

Answer 3

isotopes

Question 4

What is the atomic mass of Carbon-12?

Answer 4

12 atomic mass units (amu)

Question 5

Which isotope of hydrogen is the most abundant?

Answer 5

Protium (Hydrogen-1)

Question 6

Multiple Choice: Which of the following isotopes is radioactive? A) Carbon-12 B) Carbon-14 C) Carbon-13

Answer 6

B) Carbon-14

Question 7

What is the primary use of Carbon-14 in science?

Answer 7

Carbon-14 is used in radiocarbon dating.

Question 8

True or False: All isotopes of a given element have the same chemical properties.

Answer 8

True

Question 9

What is the formula to calculate the atomic mass of an element with multiple isotopes?

Answer 9

Atomic mass = (fraction of isotope 1 × mass of isotope 1) + (fraction of isotope 2 × mass of isotope 2) + …

Question 10

Fill in the blank: The number of protons in an atom defines its __________.

Answer 10

atomic number

Question 11

What is the atomic mass of Oxygen-16?

Answer 11

16 atomic mass units (amu)

Question 12

Multiple Choice: Which isotope of uranium is used in nuclear reactors? A) Uranium-238 B) Uranium-235 C) Both A and B

Answer 12

B) Uranium-235

Question 13

True or False: The atomic mass unit (amu) is based on the mass of a Carbon-12 atom.

Answer 13

True

Question 14

What is the significance of the atomic mass in the periodic table?

Answer 14

It helps to identify the relative mass of an element compared to others.

Question 15

Fill in the blank: Isotopes can be stable or __________.

Answer 15

unstable (radioactive)

Question 16

What determines the stability of an isotope?

Answer 16

The ratio of neutrons to protons in the nucleus.

Question 17

Multiple Choice: Which of the following isotopes has the longest half-life? A) Carbon-14 B) Uranium-238 C) Iodine-131

Answer 17

B) Uranium-238

Question 18

What is the atomic mass of Chlorine-35?

Answer 18

35 atomic mass units (amu)

Question 19

True or False: Isotopes can have different physical properties.

Answer 19

True

Question 20

Fill in the blank: The average atomic mass is often not a whole number due to the presence of __________.

Answer 20

isotopes

Question 21

What is the atomic mass of Hydrogen-2?

Answer 21

2 atomic mass units (amu), also known as Deuterium.

Question 22

Multiple Choice: Which isotope is commonly used in nuclear medicine? A) Iodine-123 B) Sodium-23 C) Helium-4

Answer 22

A) Iodine-123

Question 23

What does the term ‘mass number’ refer to?

Answer 23

The total number of protons and neutrons in an atom’s nucleus.

Question 24

True or False: The mass number can be the same for different isotopes.

Answer 24

False

Question 25

Fill in the blank: The isotopic notation for an isotope includes the element's symbol, the mass number, and the __________.

Answer 25

atomic number