Chapter 2
Chemistry

Matter
	-Anything that has mass and takes up space
	-Universal
Mass
	-measurement of the amount(quantity) of matter(stuff)
Weight
	-pull of gravity
Chemical changes are essential to all of life's processes
Classified into 4 states
	-State depends on the amount of energy/ the amount of movement in the atoms
	Solid
		Definite volume
		Definite shape
	Liquid
		Definite volume
		Indefinite shape
	Gas
		Indefinite volume
		Indefinite shape
	Plasma
		Indefinite volume
		Indefinite shape
		Composed of electrically charged particles
Elements
	-Pure substances made up of one kind of matter
	-More than 100 elements have been identified
	- most abundant in universe:
		- hydrogen (83%)
		- helium (16%)
	-30 are important to living things
	-4 most important:
		Carbon
		hydrogen
		oxygen
		nitrogen
	-Also
		- phosphorus
		- sulfur
Atoms
	
	 
		A-nucleus
		B-valence electrons
		C-protons
		D-neutrons
		E-electron shells
		F-electrons

	Smallest unit of an element
	Are really "tiney"
	Protons
		-Positive charge
		-Number of protons = atomic number
	Neutrons
		No charge
		Number of neutrons = atomic mass - atomic number
	Electrons
		-Negative charge
		-Nearly no mass(.0001257 amu / 0 amu)
		-Move around nucleus
		-Number of electrons = number of protons
	Up to seven electron shells
		-Outer shells have more energy
		-stable -  full outer shell - 8th group/family
Unstable Atoms
	-Isotopes
	-Atoms with more neutrons
	-Tend to be radioactive
	-Used in nuclear medicine
		-Radioactive tracer
		-Radioactive iodine
	-Expressed as C14  or  612C- isotope notation
Ions
	Atoms with more/less electrons
	Charged atoms
	Positive if it gave away electrons
	Negative if it gained electrons
Compounds
	2 or more atoms chemically bonded together
	Has different chemical & physical properties than the atoms that make it up
	Hindenburg Blimp
		Filled with hydrogen
		Blows up
	Chemical (aka Empirical) formula
		Shows kind and proportion of atoms that make up the compound
		i.e. 3H2O
			3-coefficient (3 H2O/water molecules)
			2- subscript (2 hydrogen atoms)
			O- element in molecule (gas necessary in combustion)
			H- element in molecule (highly flammable gas)
			Water- liquid, used to put out fires
	Structural formula
		Show kind, number, and arrangement of atoms
			Butane:
			
			Isobutene:
						 
			Both have the chemical formula C4H10
		Isomer-same chemical formula, different arrangement
		C6H12O6 is
			Glucose
			Fructose
			Galactose
	Octet rule
		Atom will give away/gain electrons to have a full outer shell
		# of electrons in the outer/valance shell determines how it will react
		There are more unstable(reactive) atoms than stable(noble gasses)
	Atoms give/take or share electrons
		Determines the type of bond
		Covalent bonds-pairs of electrons are shared
			Strong bonds
			Represented with a dash(-)
	[-] (C-H) 2 electrons are shared
	[=] (O=C=O) double covalent bond, 4 electrons are shared
				[] (N  N) triple.., 6 shared, strongest bond in nature
					Diatomic molecules
						N2, O2, H2, Cl2, F2
						O3 - takes a lot of energy, unusual, ozone
			Polar covalent bonds
							 
				Electrons take longer to orbit oxygen, so they're there more, making the oxygen end negative most of the time and hydrogen positive
		Ionic Bonds
			Electrical attraction between two oppositely charged ions
			Weak bonds
			NaCl - example