Chapter 4 Review: Atomic structure and isotopes

Front

What is the average atomic mass of an element with two isotopes: 15.0 amu (30% abundance) and 16.0 amu (70% abundance)?

Back

15.7 amu

Front

In the periodic table, which letter represents the atomic mass of an element?

Back

D

Front

How many electrons are in an atom with atomic number 34, atomic mass 74, and charge -2?

Back

36

Front

The atomic number is equal to the number of _____________.

Back

Protons

Front

What is the average atomic mass of an element with the following isotopes: 4.35% (39.946 amu), 83.79% (41.941 amu), 9.50% (42.941 amu), 2.36% (43.939 amu)?

Back

41.97 amu

Front

Define atomic number.

Back

The number of protons in the nucleus of an atom.

Front

What is an isotope?

Back

Atoms of the same element with different numbers of neutrons.

Front

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

Back

Multiply the mass of each isotope by its relative abundance (as a decimal) and sum the results.

Front

What is the significance of relative abundance in isotopes?

Back

It indicates how common each isotope is compared to others.

Front

What does the atomic mass unit (amu) represent?

Back

A standard unit of mass used to express atomic and molecular weights.