Download CHEMISTRY

CHEMISTRY
Atoms
 Smallest unit
 nucleus: center/core is most of the mass
of the atom
a. protons: + charge
b. neutrons: 0/neutral charge
 electron cloud: orbitals of electrons (-)
Element
pure substance that
can’t be broken into
other types of
matter
Distinguished by
the number of
protons
each element has its own
symbol that uses 1 or 2
letters
Atoms: isotopes
 Atomic Number: number of protons
 Atomic Mass: number of protons
and neutrons
 Isotope: different number of
neutrons
 Changes weight
 Ex: C12 vs C14
Atoms: ions
 Ion: charged atom due to gaining or losing
electrons ( Na vs Na+ )
Compounds
 Substance made up of 2 or more
elements
 EX. NaCl, H2O
Compounds
 Held together by bonds
 Covalent bonds (strong): 2 or more atoms share
electrons
 Ionic Bonds (weak): attractions between + and ions
Properties of Water
 Polar (covalent) compound
 Water has a positive (+) and
negative (-) “pole”
 Pulls apart molecules like NaCl
(ionic bond)
Water Bonding
hydrogen bonds: bonds
between Hydrogen atoms
 Ex: hold molecules of
H2O together
Bond strength:
Covalent > Ionic >Hydrogen
Chemical Reactions (rxn)
EX. NaOH + HCl  NaCl + H2O
 Reactants: compounds rearranged (left side)
 Products: compounds created (right side)
Chemical Reactions (rxn)
 Exergonic/exothermic reaction: releases
energy – feels warm
 Endergonic/endothermic reaction: requires
energy and takes it from the environment- feels
cold
 Activation Energy: amount of energy needed
to start the reaction
Energy Diagram without a
catalyst
NEED TO MEMORIZE THE
FOLLOWING ELEMENTS AND
COMPOUNDS FOR YOUR QUIZ AND
TEST!
ELEMENTS
 H: hydrogen
 O: oxygen
 N: nitrogen
 C: carbon
 Na: sodium
 Cl: chlorine
 K: potassium
 S: sulfur
COMPOUNDS
H2O: water
NaCl: sodium chloride/salt
H2SO4: sulfuric acid
HCl: hydrochloric acid
NaOH: sodium hydroxide
CO2: carbon dioxide
O2: oxygen gas
For the remainder of the
lesson…
1. GEMS Lab part 2 (due today)
2. Biochem Vocabulary #1 (due tomorrow)
Biochem Vocab #1
Word
Definition
Picture/Example
Atom
Compound
Isotope
Ion
Covalent Bond
Ionic Bond
Hydrogen Bond
Activation Energy
Draw and Label Energy Diagram on Page 37