3.2 More about Atoms Flashcards
Subatomic particles
Atoms have protons and neutrons in the nucleus and a cloud of electrons that moves around the nucleus.
How is the mass of nucleons measured?
Their mass is measured in atomic mass units.
Charge and mass of a proton
1 unit, 1+ charge
Charge and mass of a neutron
1 unit, neutral charge
Charge and mass of an electron
Almost nothing, 1- charge
Atomic number
The atomic number or the proton number is the number of protons in the nucleus of an atom.
Overall Charge
Every atom has an equal number of protons and electrons to have no overall charge.
What is the nucleon number
Protons and neutrons form the nucleus so are called nucleons. The total number of nucleons is called its nucleon number or mass number.