Number of Electrons

Atom

"The Atom"

Number of Electrons - What are Electrons?
Electrons are tiny, very light particles that have a negative electrical charge. Electrons are negatively charged, circling the nucleus, making it a neutral, orbital particle. Protons are much larger and heavier than electrons and have a positive charge.

Electrons are positively charged and located in the nucleus together with the neutrons. Electrons have a charge of +1 and a mass of approximately 1 atomic mass unit (amu).

Number of Electrons - How to find the Atomic Number of an element
Every element has a unique Element Symbol and a unique Atomic Number which can be accessed via the Periodic Table with Atomic Mass.

Protons, Electrons and Neutrons

Particle: Proton Charge: +1 Location: Nucleus of Atom
Particle: Electron Charge: -1 Location: Orbital
Particle: Neutron Charge: 0 Location: Nucleus of Atom

The Atomic number = The Number of Protons in the atom of an element
Atoms must have equal numbers of protons and electrons

Number of Electrons - How to find the Number of Electrons - Examples
The atomic number is based on the number of Protons in the atom of an element. (Note: Atoms must also have equal numbers of Electrons & Protons.) So, if we know the atomic number of an element then we also know how many Protons are in an element and therefore the number of electrons in an element.

Example 1 - Number of Protons in Gold: The element Gold (Symbol Au) has the Atomic Number of 79. Any atom that contains exactly 79 protons in its nucleus is an atom of gold. The number of protons in atom of gold is therefore 79. And as there must be an equal number of electrons and protons in an element there must also be 79 Electrons in the element.
Example 2 - Number of Protons in Silver: The element Silver (Symbol Ag) has the Atomic Number of 47. Any atom that contains exactly 47 protons in its nucleus is an atom of silver. The number of protons in atom of silver is therefore 47. And as there must be an equal number of electrons and protons in an element there must also be 47 Electrons in the element.
Example 3 - Number of Protons in Neon: The element Neon (Symbol Ne) has the Atomic Number of 10. Any atom that contains exactly 10 protons in its nucleus is an atom of gold. The number of protons in atom of gold is therefore 10. And as there must be an equal number of electrons and protons in an element there must also be 10 Electrons in the element.