Size, Mass, and Isotopes

Understand the incredibly small scale of atoms, recognizing that they possess a radius of approximately 0.1 nm (1 x 10^-10 m).

Describe the scale of a typical atomic nucleus, noting its radius is less than 1/10,000 of the entire atom (about 1 x 10^-14 m).

Understand that almost all of the physical mass of an atom is densely concentrated centrally in the nucleus.

Recall the definitive relative masses of key subatomic particles: Proton (1), Neutron (1), and Electron (very small).

Define mass number accurately as the total sum of the protons and neutrons present in an atom.

Define isotopes clearly as atoms of the exact same element that inherently have different numbers of neutrons.

Interpret standard atomic representations that distinctly show a chemical symbol accompanied by its specific mass number and atomic number.

Calculate the precise numbers of protons, neutrons, and electrons contained in an atom or ion when explicitly given its atomic number and mass number.

Relate the microscopic size and dimensional scale of atoms to understandable objects in the macroscopic physical world.