- atoms are building blcoks
- perpetually moving
- Has protons electrons and neutrons
- proton is + electron is - neutron is neutral
- held together by strong nuclear forces
- Different shells
- Element is classified by number of protons
- Carbon
- $$_{atomic-number}^{atomic-mass}\mathrm{Element}$$
- Left to roght is more electrons & protons
- more shells (valence electrons)
- Compounds = more than one kind of atom
- Mixture is w/out chem bonding
- Molecules are bonded (can be same)
- Antimatter
- matter has atoms
- has atoms with negative nuclei and pos electrons
- positron is positive electron
- antiprotons are negative protons
- antiparticles are produced using nuclear accellerators
- Dark Matter
- Unseen
- know its there because of its gravitational pull
- mysterious and ~27% of the universe