BIOL 112 Lecture Notes - Lecture 1: Electron Affinity, Atomic Number, Covalent Bond
15 Jun 2018
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BIOL 112 - FIRST LECTURE:
Atoms:
Eletro’s ass is usually egligile:
- The mass is distributed by the protons in the nucleus
o (# protons + # neutrons = mass # → Dalton (D))
- # protons = # electrons
- Atomic number: number of protons
Isotopes:
- Different number of neutrons (e.g. C14 vs. C12)
- Chemically identical, physically different
Radio Carbon Dating:
- used for fossils, bones for research, i.e. how old the bones truly are – certain amount of
C12 and C14)
- If C14 has completely decayed → fossil is old
o C14 freshly decayed, levels are short of normal → fossil is fresh
- Humans have the same amount of C14 as CO2 in the body until they die
- C14 deays whe dead, dereases the loger you’re dead
Periodic Table:
- Colu = siilar heistry
- Rows: left to right has more electrons (electron affinity)
o # row = # valence
- # of unpaired electrons = valence
- Orbitals = occupied by 1/2 electron(s)
- The 4 trends*** (draw the tables)
Covalent Bonds:
- Chemical bonds contribute 1+ electrons to create a new orbital (e.g. 2H - forming 1
covalent bond, CH4 → 4 covalent bonds)
- Made of two electrons, shared from each atom to form bonds until the outer most shell
is filled
Non-Polar Covalent Bond:
- Shared equally, no partial charges
Polar Covalent Bond:
find more resources at oneclass.com
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BIOL 112 Full Course Notes
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Document Summary
The mass is distributed by the protons in the nucleus (# protons + # neutrons = mass # dalton (d)) Different number of neutrons (e. g. c14 vs. c12) Used for fossils, bones for research, i. e. how old the bones truly are certain amount of. If c14 has completely decayed fossil is old: c14 freshly decayed, levels are short of normal fossil is fresh. Humans have the same amount of c14 as co2 in the body until they die. C14 de(cid:272)ays whe(cid:374) dead, de(cid:272)reases the lo(cid:374)ger you"re dead. Rows: left to right has more electrons (electron affinity: # row = # valence. Chemical bonds contribute 1+ electrons to create a new orbital (e. g. 2h - forming 1 covalent bond, ch4 4 covalent bonds) Made of two electrons, shared from each atom to form bonds until the outer most shell is filled. Bonds are shared unequally (e. g. h2o electron distribution more towards the o due to electronegativity partial charges)
