6.1-6.4 Flashcards
1
Q
What is matter composed of?
A
Tiny particles called atoms.
2
Q
What are atoms?
A
The building blocks of matter.
3
Q
What are atoms made of?
A
Smaller particles called neutrons, protons, and electrons.
4
Q
What are the charges of protons, neutrons, and electrons?
A
Protons are positively charged particles
Neutrons are particles that have no charge
Electrons are negatively charged particles
5
Q
Where are protons and neutrons located?
A
In the center of the atom, called the nucleus
6
Q
Where are electrons located?
A
Outside the nucleus
7
Q
What is an element?
A
A pure substance that cannot be broken down into other substances by physical or chemical means.
8
Q
How many known elements are there?
A
100.
9
Q
How many elements occur naturally?
A
92
10
Q
What are horizontal rows called?
A
periods
11
Q
What are vertical columns called?
A
groups
12
Q
What are isotopes?
A
Atoms of the same element that have the same number of protons and electrons but have a different number of neutrons.
13
Q
What does changing the number of neutrons in an atom affect?
A
Its stability.
14
Q
What happens when a nucleus breaks apart?
A
It gives off radiation that can be detected and used for many applications.
15
Q
What are isotopes that give off radiation called?
A
Radioactive isotopes
16
Q
What are compounds?
A
Pure substances formed from a specific combination of two or more different elements in a fixed ratio.
Compounds can only be broken down into simpler compounds or elements by chemical means.
17
Q
What is a chemical bond?
A
The force that holds substances together.
18
Q
What is responsible for forming chemical bonds?
A
The electrons of an atom.
19
Q
What are energy levels?
A
Areas around the nucleus in which Electrons travel around.
20
Q
How do atoms become more stable?
A
By losing electrons or attracting electrons from other atoms.
21
Q
What are covalent bonds?
A
Chemical bonds that form when electrons are shared.
22
Q
What are molecules?
A
Electrically neutral groups of two or more atoms held together by chemical bonds.
Molecules are distinguished from ions by their lack of electrical charge
23
Q
What are ions?
A
Atoms that has lost or gained one or more electrons.
Ions carry an electric charge.
24
Q
What are ionic bonds?
A
Electrical attraction between two oppositely charged atoms.
25
Which two types of elements tend to donate or accept electrons more easily than other atoms?
Metals tend to donate electrons and nonmetals tend to accept electrons.
26
What are the properties of ionic compounds?
Most ionic compounds dissolve in water, are crystalline at room temperature, and have higher melting points than compounds formed by covalent bonds.
27
What are van der Waals forces?
Attractions between molecules.
28
How do van der Waals Forces work?
When molecules come close together, the attractive forces between slightly positive and negative regions pull on the molecules and hold them together.
The strength of the attraction depends on the size of the molecule, its shape, and its ability to attract electrons.
29
What are the forces that are responsible for water droplet formation and surface tension?
van der Waals forces.
30
How do van der Waals Forces cause water droplet formation and surface tension?
The slightly positive and slightly negative charges around the water molecule are attracted to the opposite charge of other nearby water molecules.
31
How are the particles that make up atoms diagrammed?
The protons, neutrons, and electrons are represented by different colored spheres. They are differentiated according to color. The protons and neutrons are in the center of the diagram. Electrons are placed around the nucleus (containing the protons and neutrons) in a cloud formation representing energy levels.
32
What are the similarities between covalent and ionic bonds?
Both ionic and covalent bonds create molecules.
33
How are van der Waals forces described?
Van der Waals forces are attractions between molecules and are responsible for water droplet formation and surface tension.
34
What are the roles of chemical reactions in life?
Chemical reactions allow living things to grow, develop, reproduce, and adapt.
35
What are chemical reactions?
The process by which atoms or groups of atoms in substances are reorganized into different substances.
Chemical bonds are broken or formed during a chemical reaction.
36
What are clues that a chemical reaction has taken place?
Production of heat or light
Formation of a new gas, liquid, or solid
37
How might physical reactions be confused with chemical reactions?
Substances can also undergo physical changes, which change the appearance but not the composition.
38
How do written chemical equations work?
Chemical formulas describe the substances in the reaction and arrows indicate the process of change.
39
What are reactants?
The starting substances on the left side of the arrow.
40
What are products?
The substances formed during the reaction on the right side of the arrow.
41
What can the arrow in chemical equations be read as?
The arrow can be read as “yields” or “react to form.
42
What are the rules for chemical equations?
In chemical reactions, matter cannot be created or destroyed.
All chemical equations must show this balance of mass.
The number of atoms of each elements on the reactant side must equal the number of atoms of the same element on the product side.
43
What is activation energy?
The minimum amount of energy needed for reactants to form products.
44
Why are some reactions rare?
Due to the high activation energy required.
45
What are the two types of reactions?
Reactions that release energy in the form of heat are exothermic.
Reactions that absorb energy in the form of heat are endothermic.
46
What are all living things driven by?
chemical reactions
47
What are substances that lower the activation energy needed to start a chemical reaction?
Catalysts
48
What is true about catalysts?
Catalysts do not change the amount of product produced, nor are they used up during the reaction.
49
What are special proteins that are the biological catalysts that speed up the rate of chemical reactions in biological processes?
enzymes
50
What is a characteristic of enzymes?
Most enzymes are specific to one reaction.
51
What are substrates?
The reactants that bind to an enzyme.
52
What are active sites?
The specific location where a substrate binds on an enzyme.
53
What factors can affect enzyme activity?
pH, temperature, and other substances.
54
What are the parts of a chemical reaction?
Reactants and products
55
How can energy changes be related to chemical reactions?
Production of heat or light and the formation of new gas, liquid, or solid are signs that a chemical reaction has taken place.
56
What is the importance of enzymes in living organisms?
They speed up the rate of chemical reactions in biological processes.
57
How are water molecules formed?
By covalent bonds that link two hydrogen (H) atoms to one oxygen (O) atom.
58
What is the polarity of a water molecule?
Water molecules have a slightly positive end near the H atoms and a slightly negative end near the O atom.
59
What are polar molecules?
Molecules with oppositely charged regions.
60
What happens when a charged region of a polar molecule comes close to the oppositely charged region of another polar molecule?
A weak attraction forms.
61
What is a hydrogen bond?
A weak interaction involving a hydrogen atom and a fluorine, oxygen, or nitrogen atom.
A hydrogen bond is a strong type of van der Waals force
62
What is a mixture?
A combination of two or more substances in which each substance retains its individual characteristics and properties.
63
What are the two types of mixtures?
Homogeneous and heterogeneous.
64
What are homogeneous mixtures?
Mixtures with a uniform composition throughout.
65
What is another name for a homogeneous mixture?
A solution.
66
What are the two components in solutions?
Solvents and solutes.
67
What is a solvent?
A substance in which another substance is dissolved.
68
What is a solute?
The substance that is dissolved in the solvent.
69
What are heterogeneous mixtures?
When the components in a mixture remain distinct.
70
What is a suspension?
A type of heterogeneous mixture where the particles settle out over time.
71
What is a colloid?
A heterogeneous mixture in which the particles do not settle out.
72
Why do many solutes readily dissolve in water?
Because of water’s polarity.
73
What are acids?
Substances that release H+ when they are dissolved in water.
74
What are bases?
Substances that release hydroxide ions (OH−) when they are dissolved in water.
75
What determines the strength of an acid or base?
The amount of hydrogen or hydroxide ions in a solution.
76
What is pH?
The measure of concentration of H+ in a solution.
77
What are the ph values of acids and bases?
Acids have pH values < 7; bases have pH values > 7.
78
What are buffers?
Mixtures that can react with acids or bases to keep the pH within a particular range.
79
How does the structure of water make it a good solvent?
Its polarity and ability to form hydrogen bonds make it a good solvent.
80
What are the similarities and differences between solutions and suspensions?
Both solutions and suspensions are mixtures, and therefore the creation of solutions and suspensions do not cause any new chemical bonds to form.
However, the particles in solutions are smaller than the ones in suspensions.
81
What are the differences between acids and bases?
Acids have more hydrogen ions compared to water and bases have more hydroxide ions compared to water.
82
What type of molecules are organisms made of?
carbon-based molecules
83
What is the study of organic compounds, which are compounds that contain carbon?
Organic chemistry.
84
What is a component of almost all biological molecules?
Carbon
85
What atoms bond together to form a variety of important organic compounds?
Carbon atoms.
86
What are Macromolecules?
Large molecules that are formed by joining smaller organic molecules together.
87
What are monomers?
Repeating units of identical or nearly identical compounds.
88
What are polymers?
Molecules made from monomers.
89
What are the four major categories of macromolecules?
Carbohydrates
Lipids
Proteins
Nucleic acids
90
What are carbohydrates?
Compounds composed of a ratio of 1 carbon :2 hydrogen :1 oxygen
91
What is the general formula for carbohydrates?
(CH2O)n where n indicates the number of CH2O units in the chain.
92
What is the purpose of carbohydrates in life?
Carbohydrates are a central energy source in organisms, as well as functioning as cellular support in plants, fungi, and animals.
93
What are lipids?
Molecules made mostly of carbon and hydrogen that make up the fats, oils, and waxes.
94
What is the primary function of lipids?
To store energy, but they are also used to prevent water loss in plants and form the honeycomb in beehives.
95
What are proteins?
Compounds made of smaller carbon compounds called amino acids.
96
What are the properties that all amino acids share?
They are made of carbon, nitrogen, oxygen, hydrogen, and sometimes sulfur and share the same general structure.
97
How many different amino acids are there?
20
98
What are proteins responsible for?
Structural support in cells, transporting substances within and between cells, signaling within and between cells, speeding up chemical reactions, and controlling cell growth.
99
What are nucleic acids?
Complex macromolecules that transmit and store genetic information.
100
What are nucleic acids composed of?
Smaller repeating subunits composed of carbon, nitrogen, oxygen, phosphorus, and hydrogen called nucleotides.
101
What are the two types of nucleic acids in living organisms?
```
Deoxyribonucleic acid (DNA)
and Ribonucleic acid (RNA)
```
102
What is the role of carbon in living organisms?
Carbon is present in almost all molecules that are key to life.
103
What are the functions of each group of biological macromolecules?
Carbohydrates are a central energy source in organisms, as well as functioning as cellular support in plants, fungi, and animals.
A lipid’s primary function is to store energy, but they are also used to prevent water loss in plants and form the honeycomb in beehives.
Proteins are responsible for structural support in cells, transporting substances within and between cells, signaling within and between cells, speeding up chemical reactions, and controlling cell growth.
Nucleic acids transmit and store genetic information.
