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Chemistry Unit Rev.
Stack #113625
Science Terms | Definition |
---|---|
John Dalton | Atoms were spherical in shape |
Ernest Rutherford | atoms were mostly space |
Democritus | First person to define an atom |
Neils Bohr | Atom has a nucleus with electrons orbitting it |
Protons | postively charged particle in nucleus |
Neutrons | neutral charge, in nucleus |
Electron | negatively charged particle, orbits nucleus |
Isotope | atom with more or less neutrons than normal |
Ion | an atom with a postive or negative charge |
Charge | When an atom is positive or negative due to loss or gain of electrons |
# of protons | equals atomic number |
# of neutrons | equals atomic mass - atomic number |
# of electrons | equals number of protons |
valence electrons | electrons in outermost shell |
Valence shell | outer shell where bonding takes place |
diatomic molecule | when 2 atoms of the same atom combine |
physical change | change that affects size, shape, or state of matter |
chemical change | creates a new substancen |
Acid | substance that produces positive hydrogen H+ ions |
Base | negative ions (usually OH-) in a solution |
Neutral Substance | Produces Salt and water, pH of 7 |