Atomic Mass Quiz

What are isotopes?

• Different elements with the same number of protons but different numbers of electrons.

• Different types of atoms with the same number of neutrons but different numbers of protons.

• Different forms of a chemical element with varying numbers of protons and electrons.

• Variants of a chemical element with the same number of protons but different numbers of neutrons.

Tags

NGSS.HS-PS1-8

How are isotopes different from each other?

• They have different numbers of protons and electrons.

• They have different numbers of protons.

• They have different numbers of neutrons.

• They have different numbers of electrons.

What is the abundance of an isotope?

• The size of an isotope compared to other isotopes of the same element.

• The weight of an isotope compared to other isotopes of the same element.

• Relative amount or percentage of an isotope compared to other isotopes of the same element.

• The charge of an isotope compared to other isotopes of the same element.

How is the atomic mass of an element calculated?

• Sum of the masses of all naturally occurring isotopes

• Mass of the most abundant isotope

• Average of the masses of all naturally occurring isotopes

• Weighted average of the masses of all naturally occurring isotopes

What is the formula to calculate the average atomic mass?

• Sum of (mass of each isotope * relative abundance) / total number of isotopes

• Sum of (mass of each isotope * relative abundance) / total number of protons

• Sum of (mass of each isotope * relative abundance) / total number of elements

• Sum of (mass of each isotope * relative abundance) / total number of atoms

If an element has two isotopes with masses 10 and 12, and their abundances are 25% and 75% respectively, what is likely the average atomic mass of the element?

• 10.5

• 12.5

• 11.5

• 13.5

If an element has two isotopes with masses 35 and 37, and their abundances are 75% and 25% respectively, what is the average atomic mass of the element?

• 37.5

• 36

• 35.5

• 36.5

An element X has two isotopes, X-33, and X-34. X-33 is 71% abundant. Which of the following is probably the average atomic mass of X?

• 33.29 amu

• 33.5 amu

• 33.75 amu

• can't determine without knowing other isotopes % abundance