CHEMISTRY

Composition of Matter Matter - _____________ _______________________ Matter is anything that ________________ ________________ ______ – quantity of matter an object has Weight – __________ __________________

Elements ________________that cannot be broken down chemically into simpler kinds of matter More than 100 elements (__ naturally occurring, ____ man-made)

90% of the mass of an organism is composed of 4 elements (______, ________, ________ and _________) Each element unique chemical ________ Consisting of __________ ___ letter is always a _______

Atoms The ________ particle of an element that retains ____ ____ ___________of that element Properties of _____ determine the structure and properties of the matter they compose Our understanding of the structure of atoms based on _________ _______, not observation

The Nucleus _________ core Consists of ________ charged ________ and _______ ________ Positively charged Contains most of the ______ of the atom

The Protons ____ ______of a given element have the _____ _________of ________ Number of _______ called the _______ ________ The number of protons is balanced by an equal number of _____________ charged ______________

The Neutrons The number _______ slightly among atoms of the same element Different number of neutrons produces __________ of the same element

Atomic Mass Protons & neutrons are found in the ____________ of an atom Protons and neutrons each have a mass of 1 amu (________ _______ _____) The ________ _______of an atom is found by adding the number of protons & neutrons in an atom

The Electrons __________ ________ high energy particles with ____________ or ___ mass Travel at very high speeds at various distances (________ _______) from the nucleus

Electrons in the same energy level are approximately the same distance from the nucleus _______ energy levels have _______ energy than _______ levels Each level can only hold a certain number of electrons

Energy Levels Atoms have ___ energy levels The levels are K (closest to the nucleus), L, M, N, O, P, Q (furthest from the nucleus) The K level can only hold ___ electrons Levels L – Q can hold up to ____ electrons (_________ _____)

Periodic Table Elements are arranged by their atomic number on the ________ _______ The horizontal rows are called ______ & tell the number of ________ ______ Vertical groups are called ________ & tell the ____________ ________ of electrons

Compounds Most elements do not exist by themselves __________ __________ with other elements in a ___________ fashion

A __________ is a pure substance made up of atoms of _____ or ______ elements The proportion of atoms are _________ ________ __________ ___________ show the type and proportion of atoms of each element that occur in a particular compound

____________ are the ________ part of a substance that retains ____ of the properties of the substance and exists in a ______ _________ Some molecules are ________ and _________

Chemical Formulas A __________ after a symbol tells the _________ of atoms of each element H 2 0 has ________ of hydrogen & ________ of oxygen ____________ before a formula tell the number of molecules ______ represents __ molecules of oxygen or (__ x __) or ___ atoms of oxygen

The ___________ and ____________ properties of a compound _______ from the physical and chemical properties of the individual __________ that compose it

The tendency of elements to combine and form compounds depends on the number and arrangement of electrons in their outermost energy level ______ are most ________ when their ______________ energy level is _______

Most atoms are ____ stable in their natural state Tend to _______ (combine) with other atoms in order to become more stable (undergo chemical reactions) In __________ ____________ bonds are _______; atoms __________ and new chemical bonds are formed that store _______

Covalent Bonds Formed when two atoms _______ one or more ______ of ___________

Ionic Bonds Some atoms become stable by ________ or __________ ____________ Atoms that ______ electrons are called ______________ _______ (__________)

Atoms that ______ electrons are called ____________ _______ (_________) Because positive and negative electrical charges _______ each other ionic bonds form

Energy and Matter Energy The ___________________ ___________ or ______ change Occurs in various forms Can be __________ to another form Forms important to biological systems are _________, ________, ____________ and _____________ energy ________________is the energy in a system that is available for work

States of Matter Atoms are in _____________ _________ The rate at which atoms or molecules in a substance move determines its _______

Solid Molecules tightly linked together in a ____________ _________ Vibrate in place ________ __________ and ________

Liquids Molecules not as tightly _______ as a solid Maintain _________ _________ Able to ______ and ______ the ________ of container that they are in

Gas Molecules have ______ or ___ __________ to each other ______ ___ ________of the occupied container Move most _________ To cause a substance to change state, ________ energy (_____) must be added to or removed

Energy and Chemical Reactions Living things undergo ___________ of _________ ___________ as part of the life process

Many are very complex involving _________ sequences called _______________________ __________ ____________ represent chemical reactions __________ are shown on the ______ side of the equation _________ are shown on the ________ side

The number of each kind of atom must be the _____on either side of the arrow (equation must be _________) _______ may be broken or made forming new compounds

Energy Transfer Much of the energy organisms need is provided by ______ (_____) Undergoes a series of chemical reactions in which energy is released (___________________) The net ________ of free energy is called an __________ (__________) reaction

Reactions that involve a net __________ of free energy are called __________ (____________) reactions ____________ is an example Most reactions in living organisms are ___________; therefore living organisms require a constant source of __________

Most chemical reactions require ________ to begin The amount of energy needed to _____ the reaction is called ______________ _________

Certain chemical substances (___________) reduce the amount of activation energy required _____________ _________ are called ___________

________ are an important class of catalysts in living organisms Mostly _________ ___________ of different kinds Each one is _________ for a different chemical reaction

Enzyme Structure Enzymes work on substances called ____________ Substrates must fit into a place on an enzyme called the ________________ Enzymes are ______________!!

Reduction-Oxidation Reactions Many of the chemical reactions that help transfer energy in living organisms involve the transfer of ___________ (reduction-oxidation = _______ reactions)

____________________– reactant loses electron(s) becoming more positive

________________– reactant gains electron(s) becoming more negative

Solutions

Solutions A ___________ is a mixture in which 2 or more substances are _____________ _____________ in another substance

___________ is the substance __________ in the solution Particles may be ions, atoms, or molecules __________ is the substance in which the ________ is _________ ________ is the ____________ ___________

Solutions can be composed of varying proportions of a given solute in a given solvent --- vary in ____________ (measurement of the amount of solute) A ___________ solution is one in which ___ _____ __________can be dissolved ______________ _________(______) are universally important to living things

____________ of water _________ _______ of the water molecule into two _____ of opposite charge (due to strong attraction of oxygen atom of one molecule for H atom of another water molecule) H 2 O  ___ (_______ ___) + ____ (_________ ____) H + + H 2 O  _______ (______________ ____)

Acids and Bases One of the most important aspects of a living system is the degree of ________ or ___________

Acids Number of __________ ____ in solutions is ________ than the number of ____________ ___ HCl  H + + Cl -

Bases Number of __________ ____ in solution is _________ than the number of ____________ ____ NaOH  Na + + OH -

pH Scale __________ ________ comparing the relative concentrations of __________ and __________ ions in a solution ranges from __ - ___  Each pH is 10X stronger than next  e.g. ph 1 is 10 times stronger than ph 2

the _________ the pH the _______ the ______ the ______ the pH the stronger the ____ pH ______ is ________ (______)

Buffers Control of pH is very important Most _______ function only within a very _________ ___ Control is accomplished with _________ made by the body Buffers keep a neutral pH (______)

Buffers ___________ small amounts of either an ____ or _____ added to a solution Complex buffering systems _________ ______________ of your body’s many fluids at normal and _____ levels