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Flashcards in CH. 2 Chemistry Deck (25):
1

I. Matter

A. Anything that occupies space and has mass (weight)

B. Composition of Matter

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I. Matter
B. Composition of Matter

1. Elements
2. Atoms

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I. Matter
A. Anything that occupies space and has mass (weight)

A. Anything that occupies space and has mass (weight)
1. The physical (living & non-living) stuff of the universe.
2. Can exist as a solid, liquid, or gas
3. Weight (mass)
A. We quantify the amount of a substance by its mass. Under the influence of gravity on the earths surface, mass is equal to the more familiar term “weight”.

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II. Identifying Elements
A. Elements differ in the number of subatomic particles in their atoms

1. Chemical Symbol
2. Atomic Number: # of Protons the atom contains.
3. Mass Number/ Atomic Mass: Protons + Neutrons
4. Isotopes: Same # pf P+s and e-s
Vary in # of neutrons 12C, 13C, 14C
*Radioisotope: Heavy isotope, tends to be unstable, decomposes to more stable isotope.
*Radioactivity: etc

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II. Identifying Elements
A. Elements differ in the number of subatomic particles in their atoms
4. Isotopes
* Radioactivity

- Process of spontaneous atomic decay
- As some isotopes adjust to a more stable form, they will emit a measurable energy. Thus energy release is called radiation.
- We can make us a radioactive isotopes in medicine (low level radiation)

< Human body org.
Chemical, cell, tissue, organ, organ system.

< Normally cells (epithelial tissue) in the thyroid gland (organ) take up the element iodine from your diet to make a thyroid hormone. If we want to check the activity of your thyroid gland we can feed your adioactive iodine, energy emitted from your thyroid gland is captured by a machine (scanned) and used to make and image of your gland. We may see cancer tumors, an under active, overactive or normal gland. Procedure called “thyroid scan”.

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III. Electrons and Chemical Bonding

A. Electrons: energy levels called electron shells
B. Electrons closest to nucleus are most highly attracted.
C. Each shel has distinct properties: Octect rule 8,8,2. Fill closest to nucleus first.
D. Bonding interactions involve outer shell (valence)
E. Full valence shells do not form bonds: stable elements are He, Neon.
F. Reactive elements: Valence shells not full and are unstable, gain and loose electrons. Allows for bond formation, which produces stable valence shells.
Ex: C, H, O, N

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IV. Chemical Bonds
A. Ionic Bonds

1. Attractive force between oppositely charged ions.
2. Ions: are charged particles(elements)
3. Ex: NaCl
4.Will dissociate in water and form+ and - ions
NaCl_______Na+ + Cl-
5. Chemicals that are made up of atoms with ionic bonds are called salts or electrolytes.
Cations + ions; H+, K+
Anions - ions; HCO3-, OH-

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IV. Chemical Bonds
B. Covalent Bonds

1. Atoms become stable through shared electrons.
2.Single covalent bonds share one electron.
3. Double covalent bonds share two electrons.
4. Ex: CH4+, O2
5. Polarity

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IV. Chemical Bonds
B. Covalent Bonds
5. Polarity

A. Covalent bonded molecules
- some are Non-Polar
Electrically neutral as a molecule as electrons are evenly shared.

-Some are Polar
Electrons are unevenly shared
Results in a positive and negative side
Ex: H2O

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IV. Chemical Bonds
C. Hydrogen Bonds

1. Weak chemical Bonds
2. Hydrogen is attracted to negative portion of polar molecule
3. Provides attraction between molecules

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V. Molecules

A. Molecules: tow or more atoms joined together by chemical bonds
Ex: O2, N2, H2O

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V. Compounds

B. Substance composed of two or more different elements
Ex: H2O, CH4, NaCl, C6H12O6 (glucose)


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V. Compounds

C. Except: Because electrolytes are electrically attracted and not chemically combined, we do not use the term “molecule” to describe NaCl etc.

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V. Solutions

D. Solutions: two or more components physically intermixed (not chemically bound)
Ex: table salt NaCl + water, blood plasma , interstitial fluid, urine, etc.

Solvent: dissolving medium, gravest amount
Solute: The dissolved substance, NaCl, glucose, O2, CO2, Ca2+, etc.: Present in smaller amounts.

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V. Solutions
2. Concentration

2. Concentration: the amount (concentration) of a solute in the total solution is usually measured as one of the following.

- Percent of the solute in the total solution
part/ 100 whole

- Milligrams per deciliter (mg/dl ) dL=100mL
- Molarity (moles per liter) =M

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I. Matter

B. Composition of Matter
1. Elements
a. Fundamental units of matter
-They cannot be broken down into other substances.
b. 96% of life is made of 4 elements: C, H, O, N.

2. Atoms
a. Building blocks of elements
b. Atomic Structure: Nucleus (Protons +, Neutrons 0) Electrons - on the outside.

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VI. Chemical Reactions
A. Terminology

1. Reactants: reacting substances
2. Products: end product (result)
3. Metabolism: Sum of all chemical reactions
4. Ex: Reactants 4H+C > Product CH4

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VI. Chemical Reactions
B. Three major types of reactions
1. Synthesis reactions

1. Synthesis reactions:
Atoms, molecules, ions, compounds are built into more complicated forms (anabolism)
Always involves bond bond formation: A+B -> AB
Ex- Building of human muscle cells or amino acids into proteins.

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VI. Chemical Reactions
B. Three major types of reactions
2. Decomposition reactions

2. Decomposition reactions
Breaking down large molecules into smaller units (catabolism)
Bonds are broken: AB -> A+B
Ex: dietary intake of animal protein or glycogen into glucose

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VI. Chemical Reactions
3. Reversible reactions

Some chemical reactions don’t just proceed in one direction but seek “equilibrium” and may proceed in both directions.

The direction of the reaction is indicated by arrows
- An important example of how the body maintains CO2and acid balance is the carbonic acid buffering system:

CO2 + H2O H2CO3 H+ HCO-3

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VII. Inorganic Compounds

A. Lack carbon
( O2, CO2, H2O, NaCl, HCl
B. Tend to be simpler than organic compounds
Ex: H2O, NaCl (inorganic) vs. C6H12O6 (organic)

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VII. Inorganic Compounds

C. Important Inorganic Compounds in living Matter
1. Water, vital properties: High specific heat, High heat of vaporization, Polar solvent properties that forms hydration layers to shield charges, is a transport medium, its a universal solvent and do not react unless they are in a solvent

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VII. Inorganic Compounds

2. Oxygen: 20% of air we breathe is oxygen, it is essential for cells to extract energy from other compounds like ATP.

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VII. Inorganic Compounds

3. Carbon dioxide: CO2 As energy is extracted from molecules with long chains of carbon atoms, bonds are broken and carbon atoms must be removed from the body. Co2 is formed.

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VII. Inorganic Compounds
4. Salts

4. Salts
Ionic Compounds that contain cations other than H+ and anions other than OH-