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Chapter 17 & 18
Term | Definition |
---|---|
Element | Any pure substance |
Aristotle believed in what 4 elements | Air Fire Water Earth |
Alchemy | Included aspects of chemistry, philosophy, religion, metallurgy, medicine, and art |
Monotomic elements | Have 1 atom in natural state |
Diatomic elements | 2 atoms in the natural state |
Johann Dobereiner | placed elements in order of increasing Mass |
Dmitri Mendeleeve | Arranged elements into what became the modern periodic table |
Periodicity | repetition of certain properties at regular intervals |
John Newlands | Arranged elements in order of their increasing atomic masses |
Henry Moseley | Discovered how to use X-rays |
Metals | belong to families with relatively few valence electrons |
Non Metals | Hold their electrons tightly |
Octet rule | atoms generally are most stable when they have a full 8 electrons in their valence energy level |
Electron affinity | deals with the strength of attraction of electrons to UNBONDED ATOMS |
Electronegativity | deals with an atoms ability to attract and hold electrons when BONDED TO OTHER ATOMS |
Covalent bonds | Non metals share electrons |
Ionic bonds | metal/non metal electrons taken not shared |
Meatallic bonds | Metals share electrons |