Science Shepherd Biology Chapter 2 Vocabulary

Front 1

energy cycle

Back 1

1, All life forms require energy to live.
2. This energy comes from sugar molecules used to fuel chemical reactions in the cells.
3. The chemical reactions are necessary for organisms to live.
4. see diagram 2.1.1 [p. 21]

Hint 1

2.1

Front 2

photosynthesis

Back 2

1. The process by which the energy of the sun is captured by producers and used to make sugar molecules is called photosynthesis.
2. Photo = "light" and synthesis = "combining parts to make a whole"

Hint 2

2.1

Front 3

cellular respiration

Back 3

1. The biological process of an animal or plant using sugar molecules to make ATP energy molecules is called cellular respiration.
2. The process by which (1) producers produce ATP for energy from the sugars they made during photosynthesis or (2) the way that consumers produce ATP for energy from the food they eat.
3. sugar molecules ⇒ ATP energy molecules

Hint 3

2.1

Front 4

matter

Back 4

1. Anything that takes up space and has mass.
2. Matter can exist in solid, liquid, or gas forms.
3. Matter must take up space and have mass, even if it cannot be seen with our eyes.
ie. The air we breathe is composed of the matter of tiny oxygen molecules.

Hint 4

2.2

Front 5

mass

Back 5

1. Mass is the quantity of matter an object has.
2. Mass is not technically weight.

Hint 5

2.2

Front 6

changes in matter

Back 6

Matter can be changed in two different ways:
1. physical change: by cooling or heating
2. chemical change: by chemical reaction

Hint 6

2.3

Front 7

physical change

Back 7

1. Matter changes in appearance only, in a physical change.
2. Gases can be transformed into liquid, and liquids transformed into solids when energy is removed [ie. cooling].
3. Solids can be transformed into liquids and liquids transformed into gases when energy is added [ie. heating].

Hint 7

2.3

Front 8

chemical change
chemical reaction

Back 8

1. Chemical changes occur when a chemical reaction takes place resulting in changes to the actual molecules.
2. Chemical reaction means the same thing as chemical change. Most biology books use chemical reaction instead of chemical change.
3. NOTE: ⇒ means a chemical reaction is taking place. Everything to the left of the ⇒ is input. Everything to the right of the ⇒ is the result of the chemical reaction. No atoms are lost, nor gained, just rearranged from one side of the reaction equation to the other side. Think of the ⇒ as an equal sign in an equation.
ie. H₂ + O ⇒ H₂O or 2 Hydrogen atoms + 1 Oxygen atom = 1 water molecule

Hint 8

2.3
2.16

Front 9

atom

Back 9

1. The smallest, indivisible building block of matter is an atom.
2. Each atom is made up of a nucleus and an electron shell.
3. Each atom is made up of protons, neutrons, and electrons, except hydrogen which has no neutron.
4. Most of the space in an atom is empty where the electrons orbit the nucleus. If an atom were the size of an acorn and placed on the 50 yard line, the electrons would be orbiting at the outer, top rows of a large football stadium.

Hint 9

2.4
2.7

Front 10

molecule

Back 10

1. A group of two or more atoms bonded together is a molecule.
2. Molecule = 2 or more atoms bonded together
3. Atoms are more stable when bonded together as molecules.
4. Atoms bond by sharing electrons to fill their outer shells using the octet and duet rules.

Hint 10

2.4
2.15

Front 11

element

Back 11

1. A molecule of the same type atoms bonded together is called an element.
2. An element is matter composed only of one type of atom.
3. The Periodic Table lists the elements.

Hint 11

2.4
2.5

Front 12

nucleus

Back 12

The nucleus is the center part of the atom that contains protons and neutrons.
1. Protons and neutrons in nucleus.
2. Electrons orbit outside nucleus in electron shell or cloud.
3. 95% of atom's mass is in the nucleus.

Hint 12

2,5
2.7

Front 13

electron shell (energy level)
electron orbital
electron cloud

Back 13

1. The area outside the nucleus where electrons are found orbiting the nucleus is the electron shell/orbital/cloud.
2. The electrons are arranged in energy levels called electron shells or electron orbitals or electron clouds.
3. Each shell can hold a specific number of electrons
4. Electrons orbit in pairs within each shell.
5. A shell may be considered complete with 8 electrons following the octet rule. This allows other shells to form with fewer electrons. The first shell is always full with 2 electrons following the duet rule.
6. There may be more than four shells in an atom, but we will only memorize the first four levels.

Full Shell One = 2 electrons
Full Shell Two = up to 8 electrons
Full Shell Three = up to 18 electrons
Full Shell Four = up to 32 electrons

Hint 13

2.5
2.12

Front 14

subatomic particles

Back 14

1. Particles that are smaller than an atom are sub-atomic.
2. Although there are more than 3 subatomic particles, the ones we are studying are protons, neutrons, and electrons.
---(a) proton = + charge; inside nucleus
---(b) neutron = no/neutral charge; inside nucleus
---(c) electron = - charge; outside/orbiting nucleus
4. Electrons are high energy with small mass particles; protons are low energy with high mass particles. This gives them equal, opposite charges
5. Protons, neutrons, and electrons are the same in every atom. Atoms differ only in the number of subatomic particles each contains. ie. hydrogen proton = carbon proton = proton

Hint 14

2.5
2.9

Front 15

electron

Back 15

1. Electrons are negatively charged, tiny subatomic particles that orbit the nucleus of an atom in the electron shell or cloud.
2. electron = (-) charge or negative charge
3. Electron is tiny compared to the proton and neutron.
4. Electron has a much higher energy level than a proton.

Hint 15

2.5

Front 16

proton

Back 16

1. A proton is a positively charged, large subatomic particle that is located in the nucleus of an atom.
2. proton = (+) charge or positive charge
3. Proton has a mass of 1 atomic unit.
4. Proton mass = 1 atomic unit.
5. Proton, like neutron, is much larger than electron.

Hint 16

2,5
2.7

Front 17

neutron

Back 17

1. A neutron is a neutrally charged, large subatomic particle located in the nucleus of an atom.
2. neutron = neutral or no charge
3. Neutron, like proton, is much larger than electron.

Hint 17

2.5
2.7

Front 18

Bohr Model

Back 18

1. A commonly used model to describe how atoms look and interact with one another.
2. Neils Bohr calculated electrons’ orbits at different levels, because they are repelled by their equal negative charges.

Hint 18

2.6

Front 19

ion

Back 19

1. Protons and electrons have equal, opposite charges, even though the proton is much larger than the electron.
2. Usually atoms have a neutral charge, since the protons and electrons balance each other out.
3. An atom with an extra proton or electron will have a positive (+) or negative (-) charge.
4. An atom that has a positive (+) or a negative (-) charge is called an ion.
5. Ions form ionic molecules held together because of the attraction of the positive (+) to the negative (-) charge.

Hint 19

2.8
2.19

Front 20

atomic number

Back 20

The atomic number is assigned to every element and corresponds to the number of protons in the nucleus of the most common form of the element.
ie. atomic number = protons in nucleus

Hint 20

2.10

Front 21

atomic symbol

Back 21

The atomic symbol is a one or two letter abbreviation to identify an element.

Hint 21

2.10

Front 22

atomic mass

Back 22

1. The atomic mass or "weight" of an element is calculated by adding the protons and neutrons in the nucleus.
ie. protons + neutrons = atomic mass or amu
2. Electrons are not counted since they orbit outside the nucleus.
3. The result is expressed in "atomic mass units" or AMU.
4. The number of protons is constant for each element. Subtract the atomic number from the atomic mass to find out how many neutrons the element contains.
ie. atomic mass - atomic number = # neutrons

Hint 22

2.11

Front 23

atomic properties

Back 23

1. How an atom behaves when exposed to other atoms and molecules is determined mainly by the number of electrons it contains.
2. Atoms with unfilled electron shells are more reactive than those with filled shells.

Hint 23

2.13

Front 24

reactive atom

Back 24

1. An atom with unfilled energy levels is more likely to react or combine with other atoms with unfilled energy levels.
2. Oxygen, nitrogen, carbon, and hydrogen make up more than 90% of all living matter and have unfilled outer energy shells.

Hint 24

2.13

Front 25

inert atom

Back 25

An atom with filled outer energy shells is not likely to react with other atoms and is called inert.

Hint 25

2.13

Front 26

Noble gas

Back 26

The six Noble gases that occur naturally are inert, odorless, and colorless, with very low chemical reactivity due to their filled outer shells.

helium (He)
neon (Ne)
argon (Ar)
krypton (Kr)
xenon (Xe)
radioactive radon (Rn)

Hint 26

2.13

Front 27

isotope

Back 27

1. An isotope is a different form of the same element that differs only in the number of neutrons each atom contains.
2. isotope = same element with different # neutrons
ie. Carbon 12 is a normal carbon atom. Carbon 14 has two extra neutrons.

Hint 27

2.14

Front 28

octet rule
duet rule

Back 28

1. Chemical bonding to form molecules with 8 electrons filling the outer shell is the octet rule.
2. Since hydrogen and helium have only 2 electrons, they bond using the duet rule.
3. ALL atoms follow the octet rule except hydrogen and helium.

Hint 28

2.15

Front 29

chemical bond

Back 29

1. A chemical bond occurs when electrons in one atom interact with electrons in another atom causing the atoms to "stick" or bond together resulting in a molecule. ie. H + H ⇒ H₂
2. Chemical bonds ALWAYS include shared electron pairs between atoms.

Hint 29

2.16

Front 30

covalent bond
covalent chemical bond

Back 30

1. Covalent bonds are formed when electrons [in groups of 2 or pairs] are equally shared between atoms involved in a chemical bond.
2. This makes covalent bonds more stable than ionic bonds, and more difficult to break apart.
3. This also means covalent bonds have a neutral charge

Hint 30

2.17

Front 31

polar bond
polar covalent bond

Back 31

A covalent bond resulting in electrons being slightly more attracted to one atom of the bond than the other is a polar bond. This usually occurs between atoms with different size nuclei.

Hint 31

2.18

Front 32

non-polar bond
non-polar covalent bond

Back 32

A covalent bond resulting in the electrons being equally shared by the atoms of the bond is a non-polar bond. This usually occurs with same size nuclei.

Hint 32

2.18

Front 33

ionic bond

Back 33

1. An ionic chemical bond forms due to the attraction of a positive ion [with more protons than electrons] to a negative ion [with more electrons than protons].
2. The bond between the charged atoms [ions] is based purely on their charge [not by sharing electrons], so the ionic bond is weaker than the covalent bond.

Hint 33

2.19

Front 34

dissociate

Back 34

Dissociation is the "falling apart" (or dissolving) of ionic bonds in a solution.

Hint 34

2.19

Front 35

reactant

Back 35

1. The individual molecule(s) or atom(s) before going through a chemical reaction are called the reactant(s).
2. Reactants are on the left side of the ⇒ in a chemical equation.
ie. H + H + O ⇒ H₂O, where 2 hydrogen atoms and one oxygen atoms are the reactants.

Hint 35

2.20

Front 36

product
end product

Back 36

1. The individual molecule(s) or atom(s) that are the result of a chemical reaction are called the product(s) or end product(s).
2. The product is on the right side of the ⇒ in a chemical equation.
ie. H + H + O ⇒ H₂O, where one water molecule is the result of the chemical reaction.

Hint 36

2.20

Front 37

Law of Conservation of Mass
closed system

Back 37

1. Law of Conservation of Mass says that no mass can be lost nor destroyed in a chemical reaction.
2. The number of atoms in molecules on the reactant side must equal the number of atoms in molecules on the product side, even though rearranged.
3. The earth is considered a closed system where matter can not enter nor leave.
4. The Law of Conservation of Mass needs to be followed in ALL chemical reactions, which makes the reactions balanced.

Hint 37

2.21

Front 38

water

Back 38

1. Water [H₂O] is one of the most important molecules for organisms to maintain life.
2. 70-80% of matter in an organism is water.
3. Water's chemical structure has unique properties..
--(a) Excellent Solvent: H₂O is formed with polar covalent bonds, because each hydrogen atom has only one proton while oxygen has 8 protons. The polar nature of the hydrogen and oxygen bond makes it an excellent solvent for many substances.
--(b) Surface Tension: The polarity of each water molecule creates hydrogen bonds which loosely fill the space between the molecules creating "surface tension". Surface tension is what allows water bugs to skim the surface and not sink. Water bugs are actually skating across hydrogen bonds.
--(c) Maintains Temperature: The temperature of water rises and falls relatively slowly, which allows organisms to regulate their own temperatures [ie. maintain homeostasis].

Hint 38

2.22

Front 39

hydrogen bond

Back 39

Hydrogen bonds form between hydrogen and a polar molecule in a solution containing polar chemical bonds.

Hint 39

2.22

Front 40

solution

Back 40

1. A solution is an homogeneous [same throughout] combination of atoms in a liquid, solid, or gas.
2. In most organisms, the solvent of the solution is water.
3. Concentrations change in solutions. ie. 1 teaspoon of salt dissolved in a cup of water is a weaker concentration than 5 tablespoons of salt dissolved in a cup of water, though both are homogeneous salt water solutions.

Solution = solute dissolved in solvent
always less solute in a solution
always more solvent in a solution
ie. salt water = salt dissolved in water

Hint 40

2.23

Front 41

solvent

Back 41

The molecules of a solution that are in greater quantity is the solvent.

Hint 41

2.23

Front 42

solute

Back 42

The molecules of a solution that are in lesser quantity is the solute.

Hint 42

2.23

Front 43

acid

Back 43

1. A solution that has a higher concentration of hydrogen ions (H⁺) than hydroxide ions (OH⁻) is an acid.
2. acid = more hydrogen ions than hydroxide ions.
3. Measured by pH 0-6.
4. Acid is considered the opposite of base or alkaline.

Hint 43

2.24

Front 44

base

Back 44

1. A solution that has a higher concentration of hydroxide ions (OH⁻) than hydrogen ions (H⁺) is a base.
2. base = more hydroxide ions than hydrogen ions
3. Measured by pH 8-14.
4. A basic solution may also be called an alkaline solution.
5. Base or alkaline is considered the opposite of acid.

Hint 44

2.24

Front 45

alkaline

Back 45

Alkaline is another word for a base solution.

Hint 45

2.24

Front 46

pH

Back 46

1. A hydrogen atom rarely breaks away from the remaining hydroxide molecule (ion) in pure water. But there are always a few hydrogen ions (H⁺) and hydroxide ions (OH⁻) floating around in pure water.
2. The pH of a solution is based on the measurement of the concentration of hydrogen to hydroxide ions it contains. A neutral pH balance is called a 7 on the pH scale of 0 to 14. Blood and pure water are pH 7.
3. An acid is a solution which contains more H⁺ ions than OH⁻ ions. The more H⁺ ions there are, the stronger the acid. The pH of acid ranges from very strong [pH 0] to very weak [pH 6].
4. A base is a solution which contains more OH⁻ ions than H⁺ ions. The more OH⁻ ions there are, the stronger the base. The pH of a base ranges from very strong [pH 14] to very weak [pH 8].

See Figure 2.25.1
The pH scale ranges from 0 to 14.
A pH of 7 is neutral.
A pH less than 7 is acidic.
A pH greater than 7 is basic.
Bromthymol blue and litmus paper are indicators sometimes used to test pH level.

Pool water is tested daily to maintain a balanced pH.
Garden soil is tested because different plants need different growing media. Lime (which is a base) may be spread to make the acidic soil more neutral. Oak leaf mulch may be used to make the basic or neutral soil more acid.

Pure water is neutral.
But when chemicals are mixed with water, the mixture can become either acidic or basic.
Examples of acidic substances are vinegar and lemon juice.
Lye, milk of magnesia, and ammonia are examples of basic substances.

Hint 46

2.25

Front 47

indicator

Back 47

1. Various substances used to determine if a solution is an acid or a base are called indicators.
2. The indicator changes color to show either acid or base.
3. Bromthymol blue is a liquid indicator added to a solution for testing.
4. Litmus paper is dipped in a solution for testing.
5. An hydrangea is a natural indicator. Its blooms are blue in acidic soil with low pH and pink in alkaline or basic soil with high pH.

Hint 47

2.26

Front 48

PEOPLE OF SCIENCE
John Dalton
(1766-1844)
First to Theorize Existence of Atoms

Back 48

1. John Dalton was a brilliant scientist from England.
2. John Dalton was the first to propose that elements were made of tiny particles [now called atoms].
3. John Dalton deduce only one type of atom is in each element.
4. John Dalton used the scientific method to produce a vast amount of original research, including the scientific basis for color blindness.

Hint 48

2.27

Front 49

PEOPLE OF SCIENCE
Neils Bohr
(1885 - 1962)
Atom Structure and Electron Movement

Back 49

1. Neils Bohr was a Danish physicist who won the 1922 Nobel Prize in physics for his work on the structure of the atom and the radiation emanating from atoms.
2. Neils Bohr was an instructor at the University of Copenhagen, except during WWII after the Nazis invaded Denmark.
3. During WWII Neils Bohr came to the United States and was an adviser on the Manhattan Project at Los Alomos while working on the development of the atomic bomb.
4. After the war Neils Bohr returned to Denmark and became an advocate for the peaceful use of atomic energy while continuing to advance theories in quantum physics.

Hint 49

2.27

Front 50

#1 Key Chapter Point

Back 50

All life forms require energy to live. [2.1]

Hint 50

2.28

Front 51

#2 Key Chapter Point

Back 51

Everything that exists -- living and non-living -- is composed of matter. This matter can undergo physical and chemical changes. [2.2 - 2.3]

Hint 51

2.28

Front 52

#3 Key Chapter Point

Back 52

Atoms are the smallest unit of matter. Atoms are composed of protons, neutrons, and electrons. [2.4]

Hint 52

2.28

Front 53

#4 Key Chapter Point

Back 53

Protons and neutrons make up the nucleus of the atom. Electrons orbit the nucleus in shells [also called clouds or orbitals]. [2.5 - 2.14]

Hint 53

2.28

Front 54

#5 Key Chapter Point

Back 54

Atoms can link to one another by covalent or ionic bonds to form larger molecules. This occurs through chemical reactions which follow the Law of Conservation of Mass. [2.15 - 2.21]

Hint 54

2.28

Front 55

#6 Key Chapter Point

Back 55

Water is special because it is a polar molecule which is non-linear, and hydrogen bonds with other water molecules. This gives water unique properties which make it critical in the maintenance of life. [2.22 - 2.23]

Hint 55

2.28

Front 56

#7 Key Chapter Point

Back 56

The pH scale measures acidity of solutions. [2.24 - 2.26]

Hint 56

2.28