Atomic Theory Unit

Front

What is the mass number in an atomic symbol?

Back

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

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), then sum these values.

Front

What is the excited state electron configuration of sodium (Na)?

Back

2-7-2

Front

What is the maximum number of electrons that can occupy the second shell of an atom?

Back

8 electrons.

Front

Which isotope of lead is likely to be the most abundant if the average atomic mass is 207.2?

Back

Lead-207 is likely the most abundant isotope.

Front

What does the atomic number represent in an atomic symbol?

Back

The atomic number represents the number of protons in the nucleus of an atom.

Front

Define isotopes.

Back

Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons.

Front

What is the significance of the electron configuration of an atom?

Back

The electron configuration determines how an atom interacts and bonds with other atoms.

Front

What is the difference between ground state and excited state of an atom?

Back

Ground state is the lowest energy state of an atom, while excited state is when an atom has absorbed energy and electrons occupy higher energy levels.

Front

What is the formula for calculating the number of neutrons in an atom?

Back

Number of neutrons = Mass number - Atomic number.