Flashcard Review: Isotopes and Average Atomic Mass

Front

What is an isotope?

Back

Isotopes are variants of a chemical element that have the same number of protons but different numbers of neutrons.

Front

How do you calculate the average atomic mass of an element?

Back

Average atomic mass is calculated by multiplying the mass of each isotope by its relative abundance (percentage), summing these values, and dividing by 100.

Front

What is the atomic number of an element?

Back

The atomic number is the number of protons in the nucleus of an atom, which determines the element's identity.

Front

How many protons does a lithium atom have?

Back

A lithium atom has 3 protons.

Front

If an element has an atomic number of 6, how many electrons does it have?

Back

It has 6 electrons, assuming it is neutral.

Front

What is the relationship between protons and neutrons in isotopes?

Back

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

Front

What is the mass number of an atom?

Back

The mass number is the total number of protons and neutrons in the nucleus of an atom.

Front

How many neutrons are in Oxygen-16?

Back

Oxygen-16 has 8 neutrons.

Front

What is the average atomic mass of an element with isotopes of 75.23 amu (24.1%), 74.61 amu (48.7%), and 75.20 amu (27.2%)?

Back

The average atomic mass is 74.92 amu.

Front

What is the significance of the atomic mass unit (amu)?

Back

The atomic mass unit (amu) is a standard unit of mass that quantifies mass on an atomic or molecular scale.