basic chemistry:
DESCRIPTION
Basic Chemistry:. Elements & Atoms. I. Elements & Atoms. Element. _________ = A substance that cannot be broken down into simpler substances. Periodic Table 1-92 occur in _______ (natural elements) 93 and above are ___________ (man-made). nature. synthetic. Trace Elements: - PowerPoint PPT PresentationTRANSCRIPT
Elements & AtomsBasic Chemistry:
_________ = A substance that cannot be broken down into simpler substances.
• Periodic Table• 1-92 occur in _______ (natural elements)
• 93 and above are ___________ (man-made)
I. Elements & AtomsElement
naturesynthetic
Natural Elements:____ are essential to living things.Carbon (C), Hydrogen (H), Oxygen (O), Nitrogen (N) make up 96% of human mass.
Trace Elements:Found in very _______ amounts but are _________ to proper activities.• Ex. Iron,
magnesium, iodine
25 small
essential
_______ = Smallest particle of an element that has the characteristics of that element.
ATOM
1. _______ (p+) = ________ charged particles2. ________ (n) = no charge (_______)
3 Subatomic particles make up an atom:Protons positivelyNeutrons neutral
3. ________ (e-) = (________ charge) move nearly at the speed of light ; form a cloud around the nucleus
3 Subatomic particles make up an atom:Electrons
negative
1. ________ = center of atom; contains ________ & _________.
2. ______________________________ = around the nucleus
2 parts of an atom:Nucleusprotons neutronsElectron cloud/energy levels
o Atoms contain an equal number of ________ and ___________ so the overall charge of an atom is ______.
protons
electronszero
o __________ = Atoms of the same element that have different numbers of ________
II. Isotopes:Isotopes
neutrons
o Named by their ____________________
o C-12 = _____ + 6p+
o C-13 = _____ + 6p+
o C-14 = _____ + 6p+ → radioactive
II. Isotopes:atomic mass numbers6
n7n8n
o ______________ = number of _______ and/or _________ of an atom.
o Ex. Na-23 contains 11 electrons and 11 protons
o ______________ = the _____ of protons and neutrons in an atom.
o ___________________________________
III. Atomic Number & Atomic MassAtomic Number proton
selectrons
Mass Number
sum
# of protons (p+) + # of neutrons (n)
o _______________ = regions around the _________ that electrons travel.
o 1st energy level can ONLY have 2 electrons
(except Hydrogen, it has only 1 e-)
IV. Energy Levels & Diagramming Atoms:Energy Levelsnucleus
o ____________ = each energy level AFTER the first can have up to ___ electrons.
o The 3rd energy level has 18 e-
IV. Energy Levels & Diagramming Atoms:Octet Rule
8
o What atom is represented in this picture?
o ___________o How do you know?
o ___________________________________
Sodium (Na)
8
Sodium’s atomic number is 11 so it has 11 e-.
Atomic # = 2; Mass # = 3Example: Helium (He)
2p+1n
2e-
nucleus
Atomic # = 17; Mass # = 35Example: Chlorine (Cl)
17p+18n
2e- 8e-7e-
Atomic # = 6; Mass # = 14Example: Carbon (C)
6p+8n
2e- 4e-
Interactions of MatterBasic Chemistry:
o __________ = a substance made of chemically combined elements.
o Atoms bond to form __________________o Atoms need _____ in OUTER energy
level to be stable;Exception: hydrogen & helium need 2e-Open bonding sites(electrons) encourage_________.
I. Compounds and Bonding:Compound
stable compounds 8
e-
bonding
o Elements can combine in two ways”
1. __________________:Covalent bonds ________ electronsThe positively charged nucleus is ___________ to the negatively charged electrons.Water, sugars, fats and proteins are ____________________
I. Compounds and Bonding:
Covalent Bonding SHAR
Eattracted
covalent molecules
Covalent Bond: occurs between nonmetals
Examples of
Covalent
Bonding
Van der Waals Forces:
o __________ = a group of covalently bonded atoms with ___ charge.
o Ex: H2O 2 hydrogen atoms + 1 oxygen atom
o Oxygen needs _____ electrons to become stable
o Each hydrogen needs ____ electron to fill orbital
o Therefore, they ________!!
I. Compounds and Bonding:Molecule
no
two
one
SHARE
2. _______________: __________ of electrons creating
ions that attract each other = ____________
I. Compounds and Bonding:Ionic BondingTRANSFER Ionic Bond
o ______ = charged atoms because they have ________ or ______ electron(s)
o Atoms that ______ electrons become more _________
o Atoms that ______ electrons become more _________
o Atoms gain/lose electrons efficiently
I. Compounds and Bonding:Ions
gained
lostlosepositiv
e gainnegative
Ionic Bond: occurs between metals and nonmetals
o Include - ________, potassium, calcium, chloride, carbonate ions.
o Help maintain _____________ as these ions travel in and out of cells.
o Help transmit _________ among cells that allow you to see, taste, hear, feel and smell.
sodium
homeostasis
signals
Ions in living things:
o More effective to ______ an electron than to ______ an electron!!
I. Compounds and Bonding:GAIN
LOSE
o _______ = unequal distribution of charge
o Each molecule has a __________ end and a __________ end.
II. Water is Polar:Polar
positivenegative
o Ex: Water (H2O) molecule Oxygen is much stronger and therefore has a stronger ________________ than the hydrogen’s positive charge.
II. Water is Polar:
negative charge
o Because of water’s polarity, it can __________ many ionic compounds and other polar compounds such as ________.
II. Water is Polar:
dissolve
sugars
o The water molecules also ________ to each other because of __________ (unequal distribution of charge)
o The attraction of opposite charges forms a ______ bond called a _______________.
o This keeps large molecules __________!
o (Ex: proteins)
II. Water is Polar:
adhere
polarity
weakhydrogen bond together
1. _________ = the attraction between like molecules
• _________________ results from the cohesive properties of water.
• The polarity of water causes the surface layer of water molecules to act like a stretched film over the surface of the water (______________)
Ex. Water striders
III. Uniqueness of Water – due to its polarity
CohesionSurface tension
surface tension
2. Creeps up in thin tubes
________________• The polarity of
water allows _______ to get water from the ________.
• Water creeps up tubes in plant roots and stems.
III. Uniqueness of Water – due to its polarity
(capillary action)
plants
ground
• _________________________• Ice is _____ dense than water (ice floats)
III. Uniqueness of Water – due to its polarity
Expands when it freezesless
Water is Less Dense as a Solid
•Which is ice and which is water?
Water is Less Dense as a Solid
Water Ice
Chemical ReactionsBasic Chemistry:
Examples of chemical reactions
o All the chemical reactions in our bodies are called ____________.
o Breakdown and reassemble molecules in the body.
________________ are broken and formed during chemical reactions.
I. Chemical Reactions:
metabolism
Chemical Bonds
II. Writing a Chemical Equation:
• ______________ = # of molecules of a compound
• Ex: 6O2 = 6 molecules of Oxygen (O)
• 3H2O = ___ molecules of H2O
CH4 + 2O2 CO2 + 2H2O
II. Writing a Chemical Equation:
Coefficient
3
• _________ = # of atoms of an element
• Ex: CH4 = 1 atom C, 4 atoms H• CO2 = ___ atom of C, ___ atoms of
O
CH4 + 2O2 CO2 + 2H2O
II. Writing a Chemical Equation:
Subscript
1 2
• How many atoms of O are in 6O2?
____ atoms of O!
II. Writing a Chemical Equation:
12
• In ALL chemical equations the ______ number of atoms of elements are on the reactant and product side of chemical equations.
• Why?• Because the _________________________
_____________ (atoms are never created or destroyed; they are simply rearranged)
III. Balancing Chemical Equations:
same
Law of Conservationof Matter
• We balance equations so the Law of Conservation of Matter is NOT __________!
• We must always balance equations using ____________!!
III. Balancing Chemical Equations:
violated
coefficients
• ____________ can never be changed!
• Coefficients must always be place in _______ of the entire compound!
• Create an atom inventory.
III. Balancing Chemical Equations:
Subscripts
FRONT
H2 + O2 H2O
Ex: Balance the following equations so the Law of Conservation of Matter is NOT violated:
2 2
CaO + KBr K2O + CaBr2
Ex: Balance the following equations so the Law of Conservation of Matter is NOT violated:
2
Al2S3 + BaCl2 AlCl3+ BaS
Ex: Balance the following equations so the Law of Conservation of Matter is NOT violated:
3 2 3
Energy of ReactionsBasic Chemistry:
o The key to a chemical reaction is ________!
o Most compounds in living things ________ undergo chemical reactions without energy.
IV. Energy of Reactions:
energy
cannot
o ________________ = the minimum amount of energy needed for reactants to form products in a chemical reaction.
o Look at Graph A: the peak in the graph represents the amount of ________ that must be added to the system to make the reaction occur.
IV. Energy of Reactions:Activation Energy
energy
Graph A
o All living things are chemical factories driven by _________________!
o Enzymes (catalysts) need to be present in order to ________ the activation energy and allow the reaction to proceed quickly.
IV. Energy of Reactions:
chemical reactionsreduce
o Look at Graph B: the enzyme ________ the activation energy and the product will be formed sooner!
IV. Energy of Reactions:
lowers
Graph B
o __________ = a substance that lowers the activation energy needed to start a chemical reaction.
o ________ = special proteins that are biological catalysts that speed up the rate of the chemical reaction.
o Essential to life!o __________ to one reaction.
IV. Energy of Reactions:Catalyst
Enzyme
Specific
o The reactants that bind to the enzyme are called ____________.
o The specific location where a substrate binds on an enzyme is called the ____________.
How do ENZYMES work?
substrates
active site
o The active site and substrate have _______________ shapes (lock-and-key).
o Enzymes are ______ specific for the substrates that will change!
How do ENZYMES work?
complementary very
o When the enzyme-substrate complex forms, chemical bonds are ________ and new bonds ______ to produce the products.
o Enzyme releases the _________ and the enzyme can be used again.
How do ENZYMES work?
brokenform
product
1. ____ (how acidic or basic a substance is)
2. _____________• Most enzymes in humans cells
are most active at 98.6oF• pH & temperature will __________
(change the shape) of the enzyme so it will not be able to bond with the corresponding substrate!
Factors that Affect Enzymes:pHTemperature
denature
Examples of Enzymes Working:digestion
replication
break down
1. Helps with ___________
2. DNA ___________
3. Enzymes in the venom of a venomous snake ____________ the membranes of a person’s red blood cells.
Examples of Enzymes Working:1. Hard green apples _______
because of the action of enzymes
2. Photosynthesis and cellular respiration provide ________ for the cell with the help of enzymes
ripen
energy
Enzymes•The human body has over 1,000 types of enzymes.
•Each kind does one specific job. •Without enzymes, a person could not breathe, see, move, or digest food.
• IN SIMPLE LANGUAGE, ENZYMES KEEP US ALIVE!
•They regulate the digestion of our food, the production of energy, the production of hormones and other important body secretions, and the destruction of foreign substances.
Examples of EnzymesIn the Human Body:
•Amylases - Amylases break down starch chains into smaller sugar molecules. Your saliva contains amylase and so does your small intestine.
•Lactase – break simple sugars down into individual glucose molecules. (lactose intolerant people don’t have this enzyme)
•Lipases - Lipases break down fats.•Cellulases - Cellulases break cellulose molecules (from plants) down into simpler sugars. Most animals don’t have these so we depend on bacteria in our gut (approximately 3 lbs) to help us do this.
Examples of EnzymesOther enzymes:•Proteases and peptidases - Proteases and peptidases are often found in laundry detergents -- they help remove things like blood stains from cloth by breaking down the proteins.
Regulation of Enzyme ActivityTemperature, pH, and regulatory molecules can affect the activity of enzymes.•Enzymes produced by human cells work best at 98.6oF with a pH around 7.2.
•Pepsin in the stomach works best under acidic conditions.
•Most are regulated by molecules that switch them “on” or “off” as needed.
pH, Acids, BasesBasic Chemistry:
o ____ = how acidic or basic a substance is
o ______ = substance that forms H+ (hydrogen ions) in water
water
HCl H+ + Cl-(pH ______ than 7)
V. pH, Acids, Bases:pH
Acid
less
o ______ = substance that forms OH- (hydroxide ions) in water
water
NaOH Na+ + OH-
(pH ______ than 7)
V. pH, Acids, Bases:Base
more
The pH ScaleMeasurement system to indicate the concentration of H+ ions in solution.
Ranges from 0 to 14 pH 7 = neutral