basic chemistry of life
DESCRIPTION
Basic Chemistry of Life. AP Biology: Ch. 2-Chemical Context of Life. Basic Components. Atom --The smallest unit of matter that retains basic properties of an element Element --A substance that cannot be broken down into other substances; contains all of the same type of atoms - PowerPoint PPT PresentationTRANSCRIPT
Basic Chemistry of Life
Basic Chemistry of Life
AP Biology:Ch. 2-Chemical Context of Life
AP Biology:Ch. 2-Chemical Context of Life
Basic Components
Atom--The smallest unit of matter that retains basic properties of an element
Element--A substance that cannot be broken down into other substances; contains all of the same type of atoms
Compound--A substance consisting of two or more elements
Important ElementsC, H, N, O, P, S--Most common elements, very important for life
Ca,K,Na, Cl, Mg--also very important
Trace elements--needed in small amounts for important chemical reactions(ex. Fe, Zn)
Atomic Structure3 subatomic particles
Proton--positive charge (in nucleus)
Neutron--neutral charge(in nucleus)
Electron--negative charge(in orbitals)
An orbital is a region where an electron is mathematically predicted to be (probability field); More electrons, more complex the orbitals
Atomic Structure
http://drbein.net/chemistry.htmhttp://itc.gsw.edu/faculty/spea
vy/spclass/chemistry/atoms.htm
Traditional View 3D View of Orbitals
Basic Properties
Atomic Number--Number of protons; this defines the element.
Atomic Mass--SUm of protons and neutrons; Electrons almost have no weight so has little effect on total atomic mass.
Carbon (An Example)
C6
12.01
Atomic Number
Atomic Mass
How many protons and
neutrons does a carbon atom
have?
Changes to Atoms
Add/subtract protons--change element completely
Carbon (6 protons)-1 proton
Boron (5 protons)
Changes to AtomsAdd/subtract neutrons--change atomic mass, change stability of atom, creates isotopes (same element, different weight)
carbon 12 (atomic
weight of 12)
carbon 14 (atomic
weight of 14) -2 neutrons
Changes to AtomsAdd/subtract electrons--change overall charge of atom, change reactivity of atom, creates ions
Na (11 electrons), Cl (19 electrons)
Transfer 1 electron
Na+ (10 electrons), Cl- (20 electrons)
Basic Rules for AtomsAtoms always want to be stable
Radiation occurs when atoms release protons and neutrons to become stable, releasing excess energy in process (isotopes).
Will react with other atoms to become stable; create or destroy bonds, free radicals (ions)
Your AssignmentPick one element and identify its atomic number and atomic mass
Then identify common isotopes and ions that occur for that element. Note the specific differences (ex. exact change in atomic weight)
Post your findings as comments to this VoiceThread. First come, first serve--no repeats...the sooner you act the more elements you can chose from!