Atomic Number, Mass Number and Isotopes

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 an isotope?

Back

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

Front

How do you calculate the mass number?

Back

Mass number = Number of protons + Number of neutrons.

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

Can elements have the same atomic number?

Back

No, elements cannot have the same atomic number; each element has a unique atomic number.

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

How many protons does the isotope Li-7 have?

Back

Li-7 has 3 protons.

Front

If an atom has 4 neutrons and is Li-7, how many protons does it have?

Back

It has 3 protons.

Front

What is the mass number of Li-7?

Back

The mass number of Li-7 is 7 (3 protons + 4 neutrons).

Front

How many neutrons does the isotope of titanium with mass number 48 have?

Back

It has 26 neutrons (48 mass number - 22 protons).