Concepts of Matter and Energy

By: Kirstin, James, Ryan David, and Chloe

Matter •  Matter- is anything that occupies space and has

weight •  Matter can be found in 3 forms •  Solid, liquid, and gas •  Solids- have a definitive shape and volume •  Liquids- have a definitive volume but they conform

to the shape of their container •  Gases- have neither a definitive shape nor volume •  Matter can have both physical and chemical

changes •  A physical change does not alter the basic nature

of the substance •  A chemical change do alter the composition of the

substance

There are 2 types of energy

•  Kinetic- energy doing work •  Potential- inactive stored energy •  All living things are built of matter to live

and function

Forms of energy

•  Chemical energy- stored in bonds of chemical substance

•  Electrical energy- movement of charged particles

•  Mechanical energy-is directly involved in moving matter

•  Radiant energy-travels in waves, the electromagnetic spectrum

Energy forms conversions

•  Energy can go from one form to another quickly.

•  Energy can affect body temp. And also the bodies functioning.

•  When your body heats up is can be a form of Kinetic energy

•  This chemical reactions in your body is what keeps you alive and functioningeveryday.

Composition of Matter

Mackenzie, Rolanda, Sam, and Jared

Elements and Atoms •  Matter is composed of a limited number of substances called

elements. •  Cannot be broken down, •  Total 112 elements, 92 naturally and the rest artificially. •  Periodic table is where the complete listing of elements appear. •  The atom is the building block of elements and all have atomic

symbols on them to show the differences.

Atomic Structure •  Atoms have unique properties •  Protons, electrons, and neutrons, and electrical charge •  Protons =positive charge •  Electrons= negative charge •  Nuetrons=neutral charge •  Electrical charger= able to attract and repel all the different

properties. •  Which all this together in one atom weighs at 1 atomic mass unit.

Planetary and orbital models of an Atom

•  Planetary model portrays the atom as a miniature solar system. •  Orbital model the more modern model of the atomic structure. •  The atomic nucleus includes the protons and neutrons •  The nucleus is dense and positively charged •  The elements orbit the nucleus •  The orbital's are the regions around the nucleus where you would

find the electrons.

Identifying elements •  Protons, neutrons, and electrons are all a like. •  Atoms of different elements= have different electrons,

protons, and neutrons •  All known atoms can be described by adding one proton

and one electron. •  Light protons have equal number of protons and

neutrons larger have more neutrons then protons.

• 

Atomic number •  All elements have an atomic number •  Atomic number is equal to the number of protons its

atoms contain. •  Each atom has different number of protons than atoms

of any other element. •  Protons are always equaled to the number of electrons. •  The atomic number indirectly tells the number of

electrons the atoms has.

Atomic Mass Number

•  Atomic mass number of any atom is the sum of the protons and neutrons contained in its nucleus

•  ( EX. Hydrogen has one bare proton and no nuetrons. So its atomic number and atomic mass number is the same which is 1)

Atomic Weight and Isotopes •  Atomic weight is the average of the mass numbers of all the isotopes of an

element. •  Isotopes have the same number of protons and electrons but vary in the

number of neutrons they contain. •  Radioistopes are havire isotopes of atoms that are unstable and tend to

decompose to become more stble. •  Radioactivity is the process of spontaneous atomic decay. It can be

compared to a tiny exposions •  Isotopes of an element have the same atomic number but different atomic

masses. •  The atomic weight of an element is approximately equal to the mass

number of its abundant isotope

Michael Moussalli Patrick McGinn

Sydney O’Connor

Molecules and Compounds

Pages 32-33

Definitions •  Molecule – When 2 or more of the

same atoms combine chemically •  H + H H2 (Molecule) •  Compound – When 2 or more

different atoms bind together to form a molecule

•  4H + C CH4 (Compound)

Molecular Formula •  The formula that shows what different

atoms make a molecule or compound

•  H + H

•  2H + O

Chemical Equation •  The whole equation

•  H + H = H2

•  2H = O = H2O

Chemical Bonds and Chemical Reactions

Abby, Kristina, Nick, and Kenneth

What is a Chemical Reaction?

•  A chemical reaction occurs when atoms combine or separate from other atoms.

Bond Formation

•  Chemical bonds are not physical structures.

•  They are energy relationships that involve interactions between electrons of reacting atoms.

Roles of Electrons •  Electron shells- (energy

levels) fixed regions of space around the nucleus where electrons are found.

•  These shells are numbered 1 to 7, starting from the nucleus outward.

•  The currently known maximum number of electron shells is seven.

•  The closest to the nucleus are the most strongly positive charged.

•  The more distant are more likely to react with other atoms(less securely held).

Roles of Electrons (Cont.)

•  Each shell has a limit to how many electrons it can hold. (Shell 1 can hold 2, shell 2 can hold 8, etc.)

•  Valence Shells- the outermost shell in the atom. It determines the chemical behavior of the atom.

•  The electrons in inner shells do not participate in bonding.

Ionic Bonds •  Ionic bonds form when

electrons are completely transferred from one atom to another.

•  They gain or lose electrons during bonding.

•  This causes their positive and negative charges to become unbalanced which result in ions, charged particles.

Ionic Bonds (Cont.) •  Negatively charged ions are called anions. •  Positively charged ions are called cations. •  Both result when an ionic bond is formed. •  Most bonds formed under ionic bonds fall under the

category of salts.

Covalent Bonds •  Covalent bonds occur when covalent molecules

share electrons. •  In some covalent molecules the electrons are

shared equally between the atoms of a molecule. These are called Nonpolar Covalently Bonded Molecules.

•  When covalent bonds are made, the molecule formed always has a definite three-dimensional shape. (PG 35)

•  The shape determines what other molecules or atoms in can interact with.

•  The shape may also result in unequal electron-pair sharing.

Covalent Bonds (Cont.)

Hydrogen Bonds •  Hydrogen bonds are extremely weak bonds

formed when a hydrogen atom bound to one electron-hungry nitrogen or oxygen atom is attracted by another electron-hungry atom.

•  The hydrogen atoms form a bridge between the atoms.

•  Hydrogen bonds are common in water molecules (surface tension).

•  Hydrogen bonds also can be called Intramolecular bonds. These bonds help to bond different parts of the same molecule together into a special three-dimensional shape.

Patterns of Chemical Reactions

•  Chemical reactions involve the formation or destruction of bonds between atoms.

•  There are three types of chemical reactions:

•  Synthesis •  Decomposition •  Exchange

Synthesis Reaction

•  A synthesis reaction occurs when 2 or more atoms combine to form a larger more complex molecule. A + B AB

•  Synthesis reactions always involve bond formation.

•  They are energy-absorbing reactions. •  Synthesis reactions underlie all anabolic

activities that occur in body cells. •  They are important for growth and repair of old

tissue.

Decomposition Reaction •  A decomposition reaction occurs when a

molecule is broken down into smaller molecules, atoms, or ions. AB A + B

•  Decomposition underlie all catabolic processes in the body cells.

•  Decomposition Reactions are basically Synthesis Reactions in reverse.

•  Bonds are always broken and the products of the reaction are smaller.

•  Chemical energy is released.

Exchange Reaction

•  Exchange reactions involve both synthesis and decomposition reactions, both bonds are made and broken.

•  A switch is made during the reaction between molecule parts. AB + C AC + B and AB + CD AD + CB

Biochemistry: The Chemical Composition of Living Matter

Ann Marie Dean, Brett Foxworth, Casey Gurlaskie, Chase Williams

2 major classes of molecules in the body:

• Inorganic and Organic 1.  Inorganic compounds: Lack Carbon; tend to be

small and simple-ex: water, salts 2.  Organic compounds: Carbon-containing

compounds; more complex-ex: carbohydrates, lipids, proteins, nucleic acids

Inorganic Compounds

A.  Water •  Most abundant in the body (2/3) •  Properties that make water so vital: 1.  High heat capacity- absorbs and releases large amounts of

heat before its temperature changes appreciably 2.  Polarity/solvent properties-water=universal solvent o  Solvent=liquid or gas in which small amounts of other

substances (solute) can be dissolved o  Solvent+solute=solution o  Respiratory gases and waste can dissolve in water

A. Water o  Mucus and saliva use water as their solvent 3. Chemical Reactivity- •  Water=very important type of reaction •  Water molecules are added to larger bonds to digest

food and break down biological molecules (hydrolysis reaction)

4. Cushioning-water forms a cushion around organs, such as the brain, to protect it from trauma

B. Salts

•  Most plentiful salts contain calcium and phosphorus (found in bones and teeth)

•  Dissociation: when salt dissolves in the body and separates in its ions

•  Salt is vital to a body functioning •  All salts are electrolytes-substances that conduct

and electric current in a solution

C. Acids and Bases

1.  Characteristics of Acids: •  Sour taste, can dissolve metal •  Acid-a substance that can release

hydrogen ions in detectable amounts •  Acids are proton donors •  Acids in the body: hydrochloric, acetic,

carbonic •  Strong vs. weak acids

C. Acids and Bases 2. Characteristics of Bases: •  Bitter taste, slippery •  Proton accepters •  Hydroxides are common inorganic bases •  Any base containing the hydroxl ion is a strong

base •  Bicarbonate ion (in blood) is weaker •  When acids and bases mix, they form water and

salt •  Neutralization reaction-when an acid and a base

react

C. Acids and Bases 3. PH: Acid-Base concentrations •  The relative concentration of hydrogen ions in various body

fluids is measured in concentration units called PH units •  PH scale: found in 1990 by Sorensen and is based on the the

# of protons in a solution expressed in terms of moles per liter •  PH scale-0à14; 7= midpoint (neutral); 1-6 acids, 8-14 bases •  à1= stronger acid; à14=weaker base •  Living cells are extraordinarily sensitive to even slight changes

in pH •  Acid/base balance is regulated by the kidney, lungs, and a #

of chemicals called buffers (present in body fluids)

C. Acids and Bases •  Weak acids and weak bases are important to

the body’s buffers systems which act to maintain pH stability

•  Regulation of blood pH is critical •  Normal blood pH ranges from 7.35-7.45;

small changes in this threaten death •  When blood pH begins to dip into the acid

range, the amount of life-sustaining oxygen that the hemoglobin in blood can carry to body cells begins to fall rapidly to dangerously low levels

Acids and Bases

pH Scale