CH. 2 Chemistry

Question 1

I. Matter

Answer 1

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

B. Composition of Matter

Question 3

I. Matter

B. Composition of Matter

Answer 3

1. Elements

2. Atoms

Question 4

I. Matter

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

Answer 4

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”.

Question 5

II. Identifying Elements

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

Answer 5

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

Question 6

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

Answer 6

• 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”.

Question 7

III. Electrons and Chemical Bonding

Answer 7

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

Question 8

IV. Chemical Bonds

A. Ionic Bonds

Answer 8

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-
4. Chemicals that are made up of atoms with ionic bonds are called salts or electrolytes.
   Cations + ions; H+, K+
   Anions - ions; HCO3-, OH-

Question 9

IV. Chemical Bonds

B. Covalent Bonds

Answer 9

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

Question 10

IV. Chemical Bonds
B. Covalent Bonds
5. Polarity

Answer 10

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

Question 11

IV. Chemical Bonds

C. Hydrogen Bonds

Answer 11

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

Question 12

V. Molecules

Answer 12

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

Question 13

V. Compounds

Answer 13

B. Substance composed of two or more different elements

Ex: H2O, CH4, NaCl, C6H12O6 (glucose)

Question 14

V. Compounds

Answer 14

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

Question 15

V. Solutions

Answer 15

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.

Question 16

V. Solutions

2. Concentration

Answer 16

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

Question 17

I. Matter

Answer 17

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.

Question 18

VI. Chemical Reactions

A. Terminology

Answer 18

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

Question 19

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

Answer 19

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.

Question 20

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

Answer 20

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

Question 21

VI. Chemical Reactions

3. Reversible reactions

Answer 21

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

Question 22

VII. Inorganic Compounds

Answer 22

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

Question 23

VII. Inorganic Compounds

Answer 23

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

Question 24

VII. Inorganic Compounds

Answer 24

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

Question 25

VII. Inorganic Compounds

Answer 25

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.

Question 26

VII. Inorganic Compounds

4. Salts

Answer 26

4. Salts

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