Chapter 4Chapter 4

The Chemical The Chemical Basis of LifeBasis of Life

MatterMatter

All living things are All living things are made up of made up of mattermatter – – anything that has mass anything that has mass and takes up spaceand takes up space

Water, air, and your body are Water, air, and your body are different substances but are all different substances but are all made up of mattermade up of matter

NOT IN PACKETNOT IN PACKETMATTER –MATTER – solid, liquid, gas, plasma solid, liquid, gas, plasmaMOLECULESMOLECULESATOMSATOMS

SUBATOMIC PARTICLESSUBATOMIC PARTICLESProtonsProtonsElectronsElectronsNeutronsNeutrons

Mass vs WeightMass vs Weight

MassMass – the amount of – the amount of matter an object hasmatter an object has

WeightWeight – the amount of – the amount of mass an object has plus mass an object has plus the force of gravitythe force of gravity

States of MatterStates of Matter

Matter exists in 4 Matter exists in 4 different statesdifferent statesSolidSolid – definite – definite shape and volumeshape and volume

LiquidLiquid – definite – definite volume, not volume, not shapeshape

GasGas – no definite – no definite shape or volumeshape or volume

PlasmaPlasma - high - high temperature temperature ionized gasionized gas

ElementsElementsElementElement – substance – substance made up of the same type made up of the same type of atoms that can not be of atoms that can not be broken down chemically broken down chemically into a simpler kind of into a simpler kind of mattermatter

25 elements are 25 elements are important to living thingsimportant to living things4 make up 96% of the 4 make up 96% of the living matter in your living matter in your bodybodyOxygen, Carbon, Oxygen, Carbon, Hydrogen, NitrogenHydrogen, Nitrogen

Trace elementsTrace elements – elements – elements that make up less than .01 that make up less than .01 percent of body mass, but percent of body mass, but critical to healthcritical to health

Ex. 1.5 mg of Iodine each day – Ex. 1.5 mg of Iodine each day – affects affects thyroid gland thyroid gland

.004% Iron – important for O.004% Iron – important for O22

in your bloodin your blood

CompoundsCompounds

CompoundCompound – substance – substance containing 2 or more containing 2 or more elements that are elements that are chemically combined in a chemically combined in a fixed ratiofixed ratioEx. HEx. H22OO

Physical and chemical Physical and chemical properties differ between properties differ between the elements that make the elements that make up the compound and up the compound and the compound itselfthe compound itselfEx. Oxygen and Hydrogen Ex. Oxygen and Hydrogen = gases= gases

Combined = liquidCombined = liquid

AtomsAtomsAtomAtom – smallest possible – smallest possible

particle of an elementparticle of an elementGreek atoms = invisibleGreek atoms = invisible

NucleusNucleus – consists of – consists of protons and neutrons and protons and neutrons and makes up most of the mass makes up most of the mass of the atomof the atom

ProtonProton – positively charged – positively charged particleparticle

NeutronNeutron – neutral; particle – neutral; particle with no chargewith no charge

ElectronElectron – high energy, – high energy, negatively charged particle negatively charged particle with little masswith little mass

AtomsAtomsOrbitalOrbital – 3D region around a – 3D region around a

nucleus that indicates the nucleus that indicates the probable location of an electronprobable location of an electron

Each orbit holds a certain Each orbit holds a certain amount of electronsamount of electrons

1st orbit – 2 e1st orbit – 2 e 2nd orbit – 8 e2nd orbit – 8 e 3rd orbit – 8 e3rd orbit – 8 e

AtomsAtomsIn order to be stable, an In order to be stable, an atom must have its outer atom must have its outer orbit filled with electronsorbit filled with electronsEx. He and Ne both Ex. He and Ne both have 8 e in their outer have 8 e in their outer orbitsorbits

Atoms have the same Atoms have the same number of protons (+) number of protons (+) as electrons (-), as electrons (-), therefore, an atom is therefore, an atom is neutralneutral

AtomsAtomsPeriodic TablePeriodic Table – – chart that chart that summarizes and summarizes and organizes the organizes the elementselementsChemical symbolChemical symbol – letters– letters

Atomic numberAtomic number – – number of protons an number of protons an atom hasatom has

Mass numberMass number – total – total number of protons + number of protons + neutronsneutronsEx: F 9 protons 10 neutrons Ex: F 9 protons 10 neutrons = 19 atomic mass= 19 atomic mass

IsotopesIsotopes

IsotopesIsotopes – atoms of the – atoms of the same element that have same element that have the same number of the same number of protons, but different protons, but different number of neutronsnumber of neutrons

Radioactive IsotopeRadioactive Isotope – – one in which the nucleus one in which the nucleus decays over time, giving decays over time, giving off radiation in the form off radiation in the form of matter and energyof matter and energyUsed in research and Used in research and in medicinein medicine

Ionic BondsIonic BondsIonic bondIonic bond – the – the attractive force between attractive force between oppositely charged ions oppositely charged ions which form when which form when electrons are transferred electrons are transferred from one atom to anotherfrom one atom to another

IonIon – electrically – electrically charged atom or charged atom or moleculemolecule

Ex. NaClEx. NaCl

Covalent BondingCovalent Bonding

Covalent bondCovalent bond – forms – forms when two atoms share when two atoms share one or more pairs of one or more pairs of electronselectronsEx. Water Ex. Water Oxygen 6 Oxygen 6 electrons needs two electrons needs two HydrogenHydrogen

MoleculesMolecules

MoleculeMolecule – 2 or – 2 or more atoms held more atoms held together by a together by a covalent bondcovalent bondEx. HEx. H220 or O0 or O22

Models of MoleculesModels of MoleculesChemical formulaChemical formula - #’s and - #’s and types of atomstypes of atoms

Structural formulaStructural formula – how – how the atoms are linked by the atoms are linked by bondsbonds

Space filling modelSpace filling model – 3-D – 3-D model with colored spheresmodel with colored spheres

Chemical ReactionsChemical Reactions

Chemical ReactionsChemical Reactions – breaking – breaking of old and formation of new of old and formation of new chemical bonds resulting in a chemical bonds resulting in a new substancenew substanceReactantsReactants – starting materials – starting materials

for a rxnfor a rxnProductsProducts – ending materials – ending materials

in a rxnin a rxn

Acids, Bases, and pHAcids, Bases, and pH

HH22O HO H++ + OH + OH--

Hydroxide ion = OH- Hydroxide ion = OH- Hydronium ion = H+ Hydronium ion = H+

Acid Acid –– solution with solution with more H+more H+Ex. HClEx. HCl

BaseBase – solution with – solution with more OH- more OH- Ex. NaOHEx. NaOH

pH ScalepH ScalepH scalepH scale – scale range from 0- – scale range from 0-

14 that describes how acidic or 14 that describes how acidic or basic a solution isbasic a solution is0-6 acid 7 neutral 8-14 base0-6 acid 7 neutral 8-14 base

BuffersBuffers

BufferBuffer – substances that – substances that cause a solution to resist cause a solution to resist changes in pHchanges in pH

Important because the Important because the slightest change in pH can slightest change in pH can be harmful to organismsbe harmful to organismsEx. BloodEx. Blood

On the back of your On the back of your paper write:paper write:

AcidsAcids NeutralNeutral BaseBase