- Each element gives off a specific color of light ( emission spectra)
-unique to each element - If electrons absorb energy they can be bumped to a higher level
- When they fall to a lower level they release energy as light
Atomic Structure
- Atoms are made up of parts called subatomic particles
-Protons
-Neutrons
-Electrons - Atomic number equals the number of protons
Isotopes
- # of protons determine the type of element
- changing the number of neutrons changes the isotope of the element
- all isotopes have the same chemical properties
Mass Number
- mass# is the total of protons and neutrons
- Different isotopes have different mass
- ex. How many protons and neutrons are in Na?
-Na has 11 protons with mass number of 23-therefore Na has 12 neutrons and 11 protons