symbols
DESCRIPTION
Symbols. Symbols. Atomic Number- No. of protons Atomic Mass – No. of protons and neutrons (electron mass negligible) Chemical symbols found on Periodic table. Definitions. Element - Substance consisting of one type of atom. Isotope – Atom of an element with different number of neutrons. - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/1.jpg)
Symbols
![Page 2: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/2.jpg)
Symbols
Atomic Number- No. of protonsAtomic Mass – No. of protons and neutrons (electron mass negligible)Chemical symbols found on Periodic table
![Page 3: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/3.jpg)
Definitions
• Element- Substance consisting of one type of atom.• Isotope – Atom of an element with different number
of neutrons.• Molecule – Smallest unit of substance. Retains
chemical & physical properties of substance. Compose of 2 atoms held together by a bond. Atoms may be of same/different elements.
• Compound- Substance composed by chemical combination of two or more elements in definite proportions.
![Page 4: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/4.jpg)
Relationships
• Work in groups of 4 and respond to the following questions.
• Are N2, H2, and O2 elements or compounds?• Are N2, H2, and O2 atoms or elements?• Is C an atom or element?• Is H20 a molecule or a compound?
![Page 5: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/5.jpg)
Elements of Life
![Page 6: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/6.jpg)
Organic Compounds
• Carbohydrates (sugars) : Carbon, Oxygen, Hydrogen
• Lipids (fats): Carbon, Oxygen, Hydrogen, and Phosphorus
• Proteins: Carbon, Oxygen, Hydrogen, Nitrogen, and Sulfur
• Nucleic Acids (DNA, RNA): Carbon, Oxygen, Hydrogen, Nitrogen, Phosphorus
![Page 7: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/7.jpg)
Isotopes have a different # of neutrons.Isotopes have the same number of electrons and behave the
same way chemically.
![Page 8: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/8.jpg)
Radioisotopes
• Valuable research tools.• Unstable nucleus; over time gives off subatomic
particles & energy; results in stable nucleus.• Decay of radioisotopes occurs at constant rate
called half life.• Use carbon isotopes to date fossils and minerals.• Use other radioisotopes in medical tests.
![Page 9: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/9.jpg)
Isotopes
Why is the atomic mass not exactly double the atomic number?
![Page 10: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/10.jpg)
Periodic Table
![Page 11: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/11.jpg)
Bonding
• Atoms – held together by chemical bonds.• Two types – Ionic bond and covalent bond.• Ionic bond – one or more electrons
transferred from one atom to another.• Covalent bond – electrons shared between
atoms.• Van der Waals Forces – Weak attractive force
between molecules.
![Page 12: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/12.jpg)
Bonding• Compounds are held together by chemical bonds.• Electrons are involved in chemical bonding.• The outer shell (orbital) of atom is called valence shell.• Electrons in this shell are valence electrons.
![Page 13: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/13.jpg)
Bonding
•Atoms with unfilled valence shells are chemically reactive.
•Atoms seek to fill valence shell.
•Bonding fills valence shell with electrons.
![Page 14: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/14.jpg)
Ionic Bond
![Page 15: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/15.jpg)
Covalent Bond
![Page 16: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/16.jpg)
Bond Strength
• Covalent bonds are strongest bond. Takes more energy to break bond.
• Ionic bonds are weaker than covalent.• Van der Waals forces are weak attractions.Assignment:Create a graphic organizer. Compare and
contrast ionic and covalent bonds. Work with a partner.
![Page 17: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/17.jpg)
Properties of Water
• Only substance on Earth found as solid, liquid, and gas. Solid less dense than liquid state.
• Polarity• Cohesion• Adhesion• Capillary Action
![Page 18: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/18.jpg)
PolarityWater is polar- unevendistribution of electrons between hydrogen andoxygen atoms.
Hydrogen bonds- Attraction between + charged H and – charged O. One atom forms multiple H bonds.H bonds give water special properties.
![Page 19: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/19.jpg)
Cohesion
• Attraction between molecules of the same substance.
• Surface tension – tension at surface of water is related to cohesion
![Page 20: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/20.jpg)
Adhesion
• Attraction between molecules of different substances.
![Page 21: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/21.jpg)
Capillary ActionCapillary action is responsible for water moving through a plant.
Adhesion- water is attracted to roots, stems, and leaves.
Cohesion – water column is held together as it rises.
![Page 22: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/22.jpg)
Review1. What do the numbers 11 and 23 near the sodium symbol
represent?
2. Use the Bohr model on the right. How many a. How many valence electrons are available?b. What is the atomic mass of this element?c. Is this element an isotope? Why?
3. What elements are present in a protein?
4. What type of bond is occurring between the Mg and Cl?a. Which of the two elements has a higher
electro-negativity?b. What would happen to this compound in an aqueous solution?
5. On the left is a drop of water. Why doeswater make drops?
![Page 23: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/23.jpg)
Mixture/Solutions/Suspensions
• Mixture: Two or more elements/compounds physically mixed but not chemically mixed.
• Solution: Homogeneous mixture in which one substance is dissolved (solute) in another (solvent) usually water.
• Suspension: Mixture of water and non dissolved substance.
![Page 24: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/24.jpg)
Solution
• NaCl dissolves in water.• NaCl is the solute; water is the solvent.• Water surrounds the Na + and Cl-.
![Page 25: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/25.jpg)
Suspensions• Blood is an example of a suspension.• Red blood cells are suspended in a liquid called plasma.
![Page 26: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/26.jpg)
pH• A molecule of water can form ions• 1 molecule in 550 million will react to form ions.• Water has the same number of H+ and OH-; it is neutral.
• Solutions that have a higher concentration of H+ than water are acidic.• Solutions that have a lower concentration of H+ that water are basic (or greater OH -)
![Page 27: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/27.jpg)
pH Scale
7 = Neutral pHBelow 7 = acidic pHAbove 7 = basic pH
Each pH change represents a 10 fold change in the level of H+.EX: pH of 4 has 10x more H+ than pH of 5EX: pH of 5 has 10x less H+ than pH of 4
![Page 28: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/28.jpg)
Organic Molecules
• Are made of carbon.• Can be very small like CO2 to very large like a
protein.• Living organisms are made of and use organic
molecules.
![Page 29: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/29.jpg)
Carbon
• Is tetravalent; can form 4 bonds.• Bonds with many types of elements:
H,N,O,P,S• Can form many types of structures.
![Page 30: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/30.jpg)
Macromolecules
• Macromolecule – Giant molecule made from smaller molecules.
• Polymer- Large molecule consisting of similar or identical molecules linked together.
• Monomer – Subunit of polymer.• Polymerization - Process of polymer creation
![Page 31: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/31.jpg)
Polymerization
![Page 32: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/32.jpg)
Figure 5.2 The synthesis and breakdown of polymers
![Page 33: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/33.jpg)
![Page 34: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/34.jpg)
Organic Molecules
• Carbohydrates, proteins, and nucleic acids are polymers (and macromolecules).
• Lipids are macromolecules (but not polymers)• All are biomolecules.
![Page 35: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/35.jpg)
Carbohydrates
• Made of C, H, O in 1:2:1 ratio; (CH2O)
• Used for energy by all organisms, plants & some animals use them for structures.
• Monosaccharides- single sugar (monomer)
• Glucose is a monosaccharide used for energy.
![Page 36: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/36.jpg)
Carbohydrates
• Disaccharides - Two sugars• Table sugar sucrose is a disaccharide
composed of two monosaccharides glucose and fructose (fruit sugar).
![Page 37: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/37.jpg)
Carbohydrates• Polysaccharides are
polymers made of many monosaccharides.
• Examples:- Plant starch – used to store energy- Glycogen (animal starch) – used to strore energy.- Cellulose – used by plants for structure.
Cellulose
![Page 38: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/38.jpg)
Lipids
• Made from C, H mostly.• Used to store energy, for cell membranes,
water proof coverings, some hormones.• Three types of lipids
- Triglycerides- Phospholipids- Cholesterol
![Page 39: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/39.jpg)
Triglycerides
• Made of 2 components
- glycerol - fatty acid chains (3)
• Used to store energy (2x energy in a polysaccharide)
![Page 40: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/40.jpg)
Saturated vs. Unsaturated
Saturated Lipid- •Single bonds between Cs in carbon skeleton.•Each C single bonded to H. (i.e. saturated with H) •Chain straight / pack tightly /solids at RT.Unsaturated Lipid – •Some Cs double bonded • Makes kink in chain • Chains can’t pack as tightly/ oils at RT.
![Page 41: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/41.jpg)
Figure 5.11 Examples of saturated and unsaturated fats and fatty acids
![Page 42: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/42.jpg)
Saturated vs. Unsaturated
• Saturated fats - Animal fats - Raise LDL or bad cholesterol levels.
• Unsaturated fats-Vegetable fats - either help to raise HDL or good
cholesterol levels or decrease LDL levels.
![Page 43: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/43.jpg)
![Page 44: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/44.jpg)
Phospholipids•Phospholipids- glycerol,2 fatty acid chains, & phosphate group.
•Function – to make up cell membranes.
![Page 45: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/45.jpg)
CholesterolSteroids- lipids with 4 fused carbon rings.
Cholesterol is a steroid.
Function- component of animal cell membranes.
Precursor from which other steroids are made including hormones.
High levels contribute to atherosclerosis
![Page 46: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/46.jpg)
Nucleic Acids
• Made of C, H, O, N, P• Used to store and transmit genetic
information.• Two types: DNA & RNA• Monomer: Nucleotide
![Page 47: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/47.jpg)
NucleotidesNucleotides-Nitrogenous base
-Pentose (5C) sugar/ Deoxyribose in DNARibose in RNA
-Phosphate group
![Page 48: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/48.jpg)
DNA
DNA (polymer) is made by bonding nucleotides together.
Phosphate of one nucleotide is bonded to sugar of the next nucleotide.
![Page 49: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/49.jpg)
Proteins
• Made of C, H, O, N• Have many functions:
- Control chemical reaction rates – Enzymes- Form bones and muscles – Structural- Hemoglobin carries oxygen – Transport- Fight disease - Antibodies
![Page 50: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/50.jpg)
Proteins
• Are structurally diverse consistent with their many functions.
![Page 51: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/51.jpg)
Proteins
• Amino Acids – Monomer
• There are 20 amino acids.
• Proteins are made by the bonding of some configuration of the 20 amino acids
![Page 52: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/52.jpg)
Figure 5.16 Making a polypeptide chain
![Page 53: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/53.jpg)
• There are 4 levels of protein structure:•Primary•Secondary•Tertiary•Quaternary
![Page 54: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/54.jpg)
Chemical Reaction
• Changes one set of chemicals into another set of chemicals.• Reactants- enter into chemical reaction• Products – produced by chemical reaction• Involves breaking and making of chemical bonds.
![Page 55: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/55.jpg)
Energy
• Energy is released when chemical bonds are broken; reactions occur spontaneously.• Energy is absorbed when chemical bonds are formed; reactions require additional energy.• Living organisms carry out both types of chemical reactions to sustain life ; metabolism.
![Page 56: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/56.jpg)
Enzymes
• Are catalysts; speed up rate of chemical reaction.• Are proteins; biological catalysts.• Speed up reaction rates by lowering activation
energy.• Activation energy; the amount of energy needed
to get a chemical reaction started.• Lowering activation energy makes the reaction
happen faster.
![Page 57: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/57.jpg)
Enzymes
![Page 58: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/58.jpg)
Enzymes
• Enzymes provide site where reactants are brought together.
• Reactants = substrate• Substrate binds to active site of enzyme;
enzyme substrate complex• Reaction occurs.• Product released; enzyme freed for another
reaction.
![Page 59: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/59.jpg)
Enzymes
![Page 60: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/60.jpg)
Enzymes
• Enzymes are specific; enter into one type of reaction.
• Enzymes are biological molecules; can be damaged by changes in pH and temperature
![Page 61: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/61.jpg)
Digestion
• Nutrient – substance that supplies energy and raw material for growth, maintenance, and repair.- water for all of life’s activities-carbohydrates for energy- fats (lipids) for cell membranes, hormones- proteins for enzymes, structures, transport- vitamins for working with enzymes to regulate body processes- minerals such as calcium/bones, iron/hemoglobin, sodium & potassium/nerve function
![Page 62: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/62.jpg)
Calorie
• When food is burned, energy is converted to heat.
• Calorie= amt. of heat to raise the temperature of 1 g of H2O 1 degree Celsius
• c = 1 calorie C= 1,000 calories = kilocalorie
![Page 63: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/63.jpg)
Digestion
• To break down food into simple molecules that can be used by body.
• Two types of digestion:- Physical digestion: Breaking down of food into smaller pieces.- Chemical digestion: Breaking down of macromolecules, polymers into smaller molecules.
![Page 64: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/64.jpg)
Digestion-Anatomy
![Page 65: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/65.jpg)
Identify
![Page 66: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/66.jpg)
Digestion
• Mouth- Teeth tear apart food (physical digestion)- Saliva has an enzyme amylase to break down starches to complex sugars. (chemical digestion)
![Page 67: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/67.jpg)
Digestion
• Esophagus moves food from mouth to stomach.• Smooth muscles contract to swallow food.• Contractions known as peristalsis.
![Page 68: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/68.jpg)
Digestion
• Stomach continues mechanical and chemical digestion.
• Mechanical – Stomach muscles contract; mix & churn food; produce chyme.
• Chemical – HCl and pepsin (enzyme) work together to break down proteins into polypeptides.
![Page 69: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/69.jpg)
DigestionAccessory Digestive Structures• Pancreas- produces hormones to regulate blood sugar; produces enzymes to breakdown carbohydrates, lipids, proteins. (chemical)• Liver produces bile which breaks down lipids (fats) to smaller molecules. • Gallbladder stores bile.
![Page 70: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/70.jpg)
Digestion
• Small Intestine – 2 functions: complete chemical digestion and absorption of food molecules.
• Has 3 parts: duodenum, jejunum, ileum• Chemical digestion: All molecules broken
down to smallest component glucose, amino acids, fatty acids, glycerol
![Page 71: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/71.jpg)
Complete Mechanical Digestion Chemical Digestion
Mouth
Esophagus
Stomach
Small Intestine
![Page 72: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/72.jpg)
DigestionAbsorption of glucose and amino acids occurs at the villi (finger like projections). Absorbed by blood.Absorption of fats occurs at the villi; absorbed into lymph system.
![Page 73: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/73.jpg)
Digestion
• Large intestine functions: Remove water from undigested material; make vitamin K; expel waste from body.
![Page 74: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/74.jpg)
Enzyme Lab• Investigating Enzyme Activity • Introduction: Enzymes are Biological catalysts (usually proteins) that speed up the rates
of chemical reactions that take place within cells. In this investigation, you and your group will study how temperature or pH affects the activity of enzymes. The specific enzyme you will use is catalase, which is present in most cells and found in large concentrations in liver and blood cells. You will use liver homogenate as the source of catalase. Catalase promotes the decomposition of hydrogen peroxide (H2O2) in the following reaction:
2 H2O2 2 H2O + O2
• Hydrogen peroxide is formed as a by-product of chemical reactions in cells. It is toxic and
soon would kill cells if not immediately removed or broken down. (Hydrogen peroxide is also used as an antiseptic. It is not a good antiseptic for open wounds, however, as it is quickly broken down by the enzyme catalase, which is present in human cells.)
![Page 75: Symbols](https://reader035.vdocument.in/reader035/viewer/2022062305/568163fc550346895dd593d3/html5/thumbnails/75.jpg)
Enzyme LabYour assignment is to design an experiment which tests the affect of temperature/pH on the action of catalase.
There are pieces of equipment available in the classroom. In the course of designing the experiment decide which of the equipment/ glassware you will use and how many. Write this down.
1. State the purpose of the lab.2. What is the experimental hypothesis? (remember to use an “If…., then…” statement)3. Write out in detail, and sketch out if necessary, the final procedure (method) your group will follow to test your above hypothesis. 3. Have your procedure approved by the teacher.