Atomic Number and Atomic Mass

Front

What is the atomic number?

Back

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

Front

What is the atomic mass?

Back

The atomic mass is the weighted average mass of an atom's isotopes, measured in atomic mass units (amu).

Front

How do you find the mass number of an atom?

Back

The mass number is found by adding the number of protons and neutrons in the nucleus.

Front

What is the relationship between protons and electrons in a neutral atom?

Back

In a neutral atom, the number of protons equals the number of electrons.

Front

What is the atomic mass of Neon?

Back

The atomic mass of Neon is approximately 20.18 amu.

Front

If an atom has 18 protons, how many electrons does it have?

Back

If the atom is neutral, it has 18 electrons.

Front

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

Back

The mass number is 31 (15 protons + 16 neutrons).

Front

What does the atomic number tell you about an element?

Back

The atomic number identifies the element and determines its position on the periodic table.

Front

What is the significance of neutrons in an atom?

Back

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

Front

How does the atomic number relate to the periodic table?

Back

Elements are arranged in the periodic table by increasing atomic number.