U1S1-Atomic Structure and relative mass Flashcards
1
Q
Mass number
A
The total number of protons and neutrons in a nucleus of an atom.
2
Q
Atomic number
A
The total number of protons in the atom. It identifies the atom.
3
Q
Ions
A
Different numbers of protons and neutrons.
4
Q
Isotopes
A
Same number of protons but different number of neutrons.
5
Q
Relative atomic mass (Ar)
A
The average mass of an atom in an element on a scale where atom of carbon-12 is exactly 12.
6
Q
Relative isotopic mass
A
The mass of an atom of an isotope of an element on a scale where carbon-12 is exactly 12.
7
Q
Relative molecular mass
A
The average mass of a molecule on a scale where carbon-12 is exactly 12.
8
Q
Relative formula mass
A
The average mass of a formula unit where an atom of carbon-12 is exactly 12.
