Chapter 2 Flashcards

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0
Q

What is energy?

A

The ability to do work, move matter

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1
Q

What is matter?

A

Any material that takes up space

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2
Q

Name 4 major elements.

A

Hydrogen
Oxygen
Nitrogen
Carbon

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3
Q

Name the 4 parts of an elements box on the periodic table.

A

Atomic number
Element name
Element symbol
Atomic mass

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4
Q

What is an atom made up of? And where are each located?

A

Protons- nucleus
Neutrons- nucleus
Electrons- surrounds nucleus

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5
Q

What is the charge and mass of the 3 particles an atom is made up of?

A

Proton-pos (+) charge, mass of 1
Neutron- neutral charge, mass of 1
Electron- neg (-) charge, mass of 0

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6
Q

What is an ion?

A

An atom (or group of atoms) that have gained or lost an electrons, giving it an electrical charge

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7
Q

What is the atomic number represent?

A

The number of protons in an atom.

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8
Q

What is the mass number?

A

The total number of protons and neutrons in its nucleus.

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9
Q

Explain an isotope.

A

When the number of neutrons varies among atoms of the same element. (Each isotope therefore has a dif mass number)

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10
Q

What is the atomic weight?

A

Average mass (weight) of all isotopes

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11
Q

How do you determine the number of neutrons in an element?

A

Subtract the atomic number from the atomic mass

(P+N)-P= N

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12
Q

What is an element?

A

A fundamental type of substance

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13
Q

What’s an atom?

A

Smallest unit of an element that retains the characteristics of that element.

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14
Q

What is a molecule?

A

Two or more chemically joined atoms

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15
Q

What is a compound?

A

Molecules made up of two or more different elements. Exp: H2O

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16
Q

What are energy shells? And how many electrons does each one hold?

A

Orbitals carrying electrons on the same level.

The lowest energy shell holds 2 electrons, the next shells can hold up to 8.

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17
Q

When are Atoms most stable? And how does that occur?

A

They are most stable when their valence shell is full. It occurs with chemical bonds.

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18
Q

What is a valence shell?

A

Outermost occupied energy shell.

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19
Q

Name three chemical bonds.

A

Covalent, ionic, and hydrogen

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20
Q

Explain covalent bonds.

A

When 2 Atoms share pairs of electrons to fill their valence shells.

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21
Q

What are the two types of covalent bonds?

A
A nonpolar (equal) covalent bond is when both atoms exert approximately equal pull on their shared electrons.
A polar (unequal) covalent bond is when one nucleus exerts stronger pull on the shared electron.
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22
Q

What is electronegativity?

A

The measure of an atom’s ability to attract electrons.

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23
Q

In the molecule H2O, describe which Atom has slightly negative charge and which atom has slightly positive charge and why?
H (2.2)
O (3.4)

A

The two hydrogen atoms are slightly positive (+) and the oxygen atom is slightly negative (-) because of the electronegativity difference. Oxygen has stronger pull.

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24
Q

What happens in an ionic bond?

A

When one atom transfers electrons to another Atom because of the electrical attraction between two ions with opposite charges.

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25
Q

An Atom that loses an electron is…

An atom that gains an electron is…

A
Positively charged
Negatively charged
(Ions)
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26
Q

If Na has 11 electrons, that leaves 1 in the valence shell. Cl has 17, leaving 7 in valence shell. Explain the bond that can occur and why.

A

An ionic bond will occur because the one electron in sodium will be donated to the chlorine atom to fill its valence shell making them both stable. This creates ions sodium (+) chloride (-) also known as table salt.

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27
Q

What is a hydrogen bond?

A

Weak chemical bond between opposite partial charges onto molecules or within one large molecule.
H20 to H20

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28
Q

What is a chemical reaction?

A

When Two or more molecules swap their atoms to yield different molecules.

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29
Q

What is the reactant?

A

Starting material

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30
Q

What is the product?

A

Result of reaction

Exp:
CH4 + 2O2 —-> CO2 + 2H2O
methane + oxygen –> carbon dioxide+ water

31
Q

What are five properties of water?

A

Cohesion
Solvent
Evaporating (regulates temps)
Freezing (stable bonds, less dense) Chemical reactions (reactant or product of many)

32
Q

What is cohesion?

A

The tendency of water molecules to stick together

33
Q

How do water molecules stick together?

A

Hydrogen bonds

34
Q

What is a solvent?

A

Chemical in which other substances dissolve

35
Q

What is a solute?

A

Dissolved substances

36
Q

What is a solution?

A

One or more solutes dissolved in a liquid solvent

37
Q

Scientist divide chemicals into two categories based on solubility in water. What are they? Explain.

A

Hydrophilic-Substances are either polar or charged so they are readily dissolved in water (water loving).
Hydrophobic-nonpolar molecules made mostly of carbon and hydrogen, they do not dissolve, or form bonds, in water (water fearing).

38
Q

The polarity (+,-) of water molecules helps water dissolve ____.

A

Ions

39
Q

What is evaporation?

A

The conversion of liquid into vapor

40
Q

The pH scale is based on The amount of _____ in a solution.

A

H+

41
Q

Acidic solutions have a ____ pH and a ____ H+ concentration.

A

Low

High

42
Q

Basic solutions have a ____ pH and a ____ H+ concentration.

A

High

Low

43
Q

Bases have more ____ ions than ____ ions.

A

OH-

H+

44
Q

PH scale range is ____.

A

1-14

45
Q

Neutral on the pH scale is considered ____.

A

7

46
Q

What is a buffer system?

A

Pairs of weak acids and bases that resist pH changes.

Solution that consumes or releases H+ to maintain constant pH.

47
Q

What is pH for?

A

Scale that measures how are acidic or basic a solution is, & measurement of # H+ ions

48
Q

What does neutral represent on the pH scale?

A

Same amount of H+ as OH-

49
Q

What is an acid?

A

Molecules that release H+ when dissolved in H2O

50
Q

What is a base?

A

Substance that removes H+ from solution

51
Q

What are the four main types of organic molecules?

A

Proteins lipids carbohydrates and nucleic acids

52
Q

What two elements do organic molecules contain?

A

Carbon and hydrogen

53
Q

What is a monomer?

A

Single unit of a carbohydrate protein or nucleic acid

54
Q

What is a polymer?

A

Joined monomers

55
Q

What is dehydration synthesis?

A

An enzyme binding to monomers releasing a water molecule (h2o)

56
Q

What is hydrolysis?

A

The reverse reaction of dehydration synthesis. Water (h2o) is used to break polymers into monomers.

57
Q

What are the monomers and polymers of carbs?

A

Monosaccharides and polysaccharides

58
Q

What are the most common polysaccharides? (4) and their function.

A

Cellulose-plant structure
Starch-Storage molecules (plants)
Glycogen- storage molecules (animal/fungal)
Chitin-cell wall (insects/fungi)

59
Q

Lipids are not built from chains of monomers, true or false?

A

TRUE

60
Q

What are two groups of lipids?

A

Triglycerides and sterols

61
Q

What does a triglyceride contain?

A

Glycerol link to three fatty acid’s

62
Q

What is glycerol?

A

A three carbon molecule that forms the triglycerides backbone

63
Q

What are fatty acids?

A

Three long hydrocarbon chains with a carboxyl group at the top (c=o)

64
Q

Name the two types of fatty acid. Explain their differences.

A

Saturated, “saturated with hydrogen” and is solid at room temperature the chains are straight.
Unsaturated, kinked chains

65
Q

What are sterols?

A

Lipids that have for interconnected carbon rings. Example cholesterol.

66
Q

What is the monomer and polymer of protein?

A

Amino acids and proteins

67
Q

What is the general structure of amino acids?

A

Central Carbon Atom, linked with an amino group, carboxyl group, and R group (variable).

68
Q

How are dipeptide, tripeptide and polypeptides formed?

A

Dehydration synthesis, linking two, three, and more (long chains) of amino acids.

69
Q

What is a peptide bond?

A

Covalent bond that links each amino acid to its neighbor

70
Q

What are the four levels of protein structure? And explain.

A

Primary (1): linear amino acid sequence of the polypeptide chain
Secondary (2): The first folding of amino acids into coils cheats and loops resulting from hydrogen bonds between parts of the polypeptide.
Tertiary (3): overall shape of a polypeptide, interacting with the R group, enzymes,more folding,hydrogen bonds, covalent bonds.
Quaternary (4): overall protein shape arising from the interactions between multiple polypeptide subunits of the same protein.

71
Q

What is Denatured?

A

If it’s structure is modified enough to destroy its function. Examples heat, excessive salt, and wrong pH can destroy the hydrogen bonds that maintain second and tertiary structure

72
Q

What are the monomers and polymers of nucleic acid?

A

Five nucleotides

And nucleic acids

73
Q

What are the two types of nucleic acid’s?

A

DNA and RNA

74
Q

What are the three basic components of nucleotides?

A

Five carbon sugar (2), nitrogenous base (5), and a phosphate group

75
Q

What are the two types of five carbon sugar’s?

A

Deoxyribose (DNA) ribose (RNA)

76
Q

What are the five types of nitrogenous bases? And which sugar uses each?

A

(Both DNA/RNA): Adenine cytosine guanine

(DNA): thymine
(RNA): uracil