Nucleus
Allotropes
Substance
Electrons
Average Atomic Mass
Colloid
Groups
Mass number
is a type of matter with a fixed composition.
is a type of suspension.
are the vertical columns in the periodic table.
are different forms of the same element.
Is the weighted average mass of its isotopes.
is the sum of the number of protons and neutrons.
is the center of an atom.
are the particles in a atom with a negative charge.
