The atomic mass of an atom is calculated by adding up what two subatomic particles

The atomic mass of an atom is calculated by adding up protons and neutrons

Further explanation

There are two components that accompany an element, the mass number and atomic number

Atoms are composed of 3 types of basic particles (subatomic particles): protons, electrons, and neutrons

The charge of 1 proton is equal to a charge of 1 electron but has a different sign

The proton is positively charged (+1), the electron is negatively charged (-1). and neutrons not charged (neutral)

The Atomic Number (Z) indicates the number of protons and electrons in an atom of an element.

Atomic number = number of protons = number of electrons ⇒ neutral number

Atomic mass is the sum of protons and neutrons

Atomic Number (Z) = Atomic mass (A) - Number of Neutrons

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