Atomic Number and Mass Number

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

What is the atomic number of an atom?

Back

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

Front

How do you calculate the mass number?

Back

Mass number = Number of protons + Number of neutrons.

Front

What is the relationship between atomic number and element identity?

Back

The atomic number determines the identity of an element; each element has a unique atomic number.

Front

If an atom has 12 protons, what is its atomic number?

Back

The atomic number is 12.

Front

What is the mass number of a Magnesium atom with 12 protons and 12 neutrons?

Back

The mass number is 24.

Front

How many neutrons are in a fluorine atom with 9 protons and 10 neutrons?

Back

There are 10 neutrons.

Front

What is the mass number of a phosphorus atom with 15 protons and 16 neutrons?

Back

The mass number is 31.

Front

If an atom has an atomic number of 9, how many electrons does it have?

Back

It has 9 electrons, assuming it is neutral.

Front

What is the significance of neutrons in an atom?

Back

Neutrons contribute to the mass of an atom and can affect its stability.