Systems, Matter, & Energy Chapter 2

Friday, August 14th, 2015

Chapter Overview Questions What are major components and behaviors

of complex systems? What are the basic forms of matter, and

what makes matter useful as a resource? What types of changes can matter undergo

and what scientific law governs matter? How are the scientific laws governing

changes of matter from one form to another related to resource use, environmental degradation and sustainability?

Systems– Systems: set of interacting

components connected in such a way that a change in one part affects 1+ other parts of the system

The earth is the largest system that environmental science looks at

The Effects of water diversion on Lake Mono

Matter Nature’s Building Blocks;anything that has massand takes up space Types of Matter:

– elements – single type of atoms, cannot be broken down into other substances• 92 natural +18 synthesized

– compounds - 2 or more different elements, held together by chemical bonds

(fixed proportions) ex: H2O

Elements Important to the Study of Environmental Science

8 elements make up 98.5% of the Earth’s crust

Compounds Important to the Study of Environmental Science

Building Blocks

Atoms – smallest unit of matter Elements – Composed of atoms,

cannot be broken into simpler components– Atomic theory: all elements made up of

atomsMolecules – Two or more atoms of the

same or different elements held together by chemical bonds

ex: H2, O2, N2

Basic Chemistry Terms

Atomic Number - # of protons

Subatomic particles– Protons (p+) with positive charge and

neutrons (n0) with no charge in nucleus– Negatively charged electrons (e-) orbit

the nucleusMass Number – protons (p+) + neutrons(n0)

Basic Chemistry Terms

Atoms, Ions, and Molecules Are the Building Blocks of Matter Ions- electrically

charged atom or combination of atoms– Metals: lose e-

– Nonmetals: gain e-

pH– Measure of acidity– Neutral = 7– Acid (H+ ions) = 1-6– Base (OH- ions) =

8-14

Ions Important to the Study of Environmental Science

Ions Important to the Study of Environmental Science

Isotopes Elements with

same atomic number but a different mass #(C12, C13 & C14)

Atoms, Ions, and Molecules Are the Building Blocks of Matter

Ionic bonds - gaining/losing electronsmade up of opposite charged ions Na+ Cl- (the

charge imbalance holds them together)Covalent bonds - sharing electrons

uncharged atoms methane: CH4

Chemical formula – type of short hand to show the type and # of atoms/ions in a compound. Ex. NaCl or CH4

Atoms, Ions, and Molecules Are the Building Blocks of Matter

Atoms, Ions, and Molecules Are the Building Blocks of Matter

Hydrogen bond- covalently bonded H atoms are attracted to another atom on a different molecule

(weaker than ionic and covalent bonds)Polar bond- unequal sharing of electrons One side becomes slightly positively charged,

the other slightly negative

Brain Break: Review Relay Each team will get a list of questions to

answer. Each question must be answered in

order & one at a time. Run up to Miss Scott, get your answer

checked, and go back to your table to answer the next question. You must run around the room and back to your table

Each team member must take a turn coming up to get the answer checked.

Organic Compounds

Contain carbon and hydrogen– Hydrocarbons C8H18 gasoline and

chlorinated hydrocarbons C14H9Cl5 DDT

– Simple carbohydrates C6H12O6

– Macromolecules: complex organic molecules

Organic Compounds: Macromolecules

Carbohydrates– C, H and O – used as quick energy source– Made up of monosaccharides (glucose)

Proteins– Used for structural support, transport,

defense and as enzymes (control rate of chemical reactions)

– Made up of amino acids (nitrogen containing organic molecules)

Organic Compounds: MacromoleculesNucleic Acids

– Found in all living cells• DNA: genetic material• RNA: used to synthesize proteins

Lipids– Used for long-term energy storage (fats)– Make up membranes– Do not mix with water

Inorganic Compounds

No carbon to carbon or carbon to hydrogen bonding, not originating from a living source– Earth’s crust – minerals, water– Water, nitrous oxide, nitric oxide, carbon

monoxide, carbon dioxide, sodium chloride, ammonia

Matter Occurs in Various Physical Forms Solid

Liquid

Gas

High-quality matter

Low-quality matter

Matter Quality: High or Low A measure of how useful matter is for

humans based on availability and concentration.

Matter Undergoes Physical, Chemical, and Nuclear Changes

Physical change - chemical composition not changed ex: ice melts

Chemical change - chemical composition has changed

Nuclear change– Natural radioactive decay

• Radioisotopes: unstable– Nuclear fission (split apart)– Nuclear fusion (fuse together)

Nuclear Changes

Nuclei of certain isotopes are unstable… so they are radioactive.

Radioactive isotopes undergo radioactive decay, spontaneous release of material from the nucleus– Changes radioactive element into a different

element

Beta particle (electron)

Radioactive decay

Radioactive isotope

Alpha particle(helium-4 nucleus)

Gamma rays

Nuclear fissionUranium-235

Energy

Energy

Energy

Energy

Fissionfragment

Fissionfragment

Neutronn

Uranium-235

nn

n

n

n

Nuclear fusion

FuelProton Neutron

Hydrogen-2(deuterium nucleus)

Hydrogen-3(tritium nucleus)

Reactionconditions

100million °C

ProductsHelium-4 nucleus

Energy

Neutron

Half - Life

Time needed for one-half of the nuclei in a radioactive isotope to decay and emit their radiation.

Signficance: Some elements emit harmful radiation (so we can know how long it’s dangerous for if we know it’s half-life).

Carbon Dating Carbon-14 is radioactive and it’s half-life is

5370 years. Organisms incorporate carbon into their

tissues at ~atmospheric ratio (When it dies, stops incorporating & C inside starts to decay)

Can measure the proportion of C-14 and determine how many years ago the organism died.

Chemical Reactions

Molecules separate into atoms and recombine** notice same number of atoms of each element on each side

We Cannot Create or Destroy MatterLaw of conservation of matter

– no atoms are created/destroyed during a physical or chemical change.

Matter consumption– Matter is converted from one form to

another

“Energy Flows & Matter Cycles”

Matter is neither created nor destroyed, it just changes form and cycles throughout the system (our earth).