Atom Flashcards
1
Q
Atom
A
The smallest unit of matter that has the properties of an element
2
Q
Proton
A
Positively charged subatomic particle in the nucleus (+1)
3
Q
Neutron
A
Natural subatomic particle in the nucleus
4
Q
Electron
A
Negatively charged subatomic particle outside the nucleus (-1)
5
Q
Nucleus
A
Center of an atom, it has protons + neutrons
6
Q
Atomic number
A
Number of protons in a atom identifies the atom
7
Q
Mass number
A
Total number of protons + neutrons
8
Q
Group
A
Column on the periodic table, has the same number of valance electrons
9
Q
Period
A
Row on the periodic table
10
Q
Valence electron
A
Electrons in the outermost energy shell. They determine reactivity.
