Question

electron
proton

• has a charge
• located in the
• gives an its

the mass of an atom/element is due to which two particles?
and
neutron

• has no charge ()
• located in the nucleus
• found by atomic number

from atomic mass
atomic
mass

• usually a
• equal to the number of protons

the average number of neutrons

Explanation:

Proton

Step1: Charge

Protons have a positive charge.

Step2: Location

They are located in the nucleus of an atom.

Step3: Element Identity

Protons give an atom (and by extension an element) its identity (as the number of protons defines the element).

Mass - Contributing Particles

Step1: Mass - Contributing Particles

The mass of an atom/element is mainly due to protons and neutrons (as electrons have negligible mass compared to them).

Neutron

Step1: Charge

Neutrons have no charge (they are neutral).

Step2: Calculation

The number of neutrons in an atom is found by subtracting the atomic number from the atomic mass (since atomic mass ≈ protons + neutrons and atomic number = protons).

Atomic Mass

Step1: Value Type

Atomic mass is usually a decimal (as it is the weighted average of the masses of an element's isotopes).

Step2: Composition

It is equal to the number of protons plus the average number of neutrons.

Answer:

• Proton: positive, nucleus, atom, identity
• Mass - Contributing Particles: protons, neutrons
• Neutron: neutral, subtracting
• Atomic Mass: decimal, plus