-
Protons
- positive particles inside the nucleus
- Mass is about 2,000 times that of an electron
-
Atomic Number
- number of protons in the nucleus
- all atoms of the same element have the same atomic number
-
Neutrons
- have no charge
- about the same mass as a proton
-
Isotopes
- an element that has the same number of protons, but different masses
- one of two or more atoms with the same atomic number but with different numbers of neutrons
- A lack of necessary neutrons makes a nucleus unstable
-
Most Famous Isotope
- 235U - uranium
- creates nuclear energy and weapons
-
mass number
- sum of the protons and neutrons in an atom
- changes for different isotopes of an element
- ex: C-12 (6p+6n) C-13 (6p+7n)
-
atomic number
- number of protons
- same for all atoms of an element
- Carbon (C) atomic number = 6 (6p)
-
atomic mass
- average mass of atoms of the element
- usually not a whole number
- atomic mass of carbon = 12.011
|
|
