Chapter 2: The Chemical Context of Life

Question 1

Compound

Answer 1

made of atoms joined by bonds, a substance consisting of 2+ different elements combined in a fixed ratio

Question 2

Element

Answer 2

a substance that can not be broken down to other substances by chemical reactions

Question 3

Protons

Answer 3

number determines an atoms identity, positive charge

Question 4

Electron Distribution

Answer 4

determines its ability to form bonds, how many electrons are in each shell surrounding the protons and neutrons

Question 5

Trace Elements

Answer 5

some are needed in all forms of life but only in minutely small amounts

Question 6

Most Common Atoms in Living Matter

Answer 6

oxygen, carbon, nitrogen, hydrogen

Question 7

Atom

Answer 7

smallest unit of matter that still retains properties of an element

Question 8

Subatomic Particles

Answer 8

tiny bits of matter composing even smaller parts

Question 9

Neutrons

Answer 9

neutral charge

Question 10

Electrons

Answer 10

negative charge, in the rings around the center of neutrons and protons, same amount of electrons as protons to balance out the charge of the atom

Question 11

Atomic Nucleus

Answer 11

protons and neutrons packed tightly in a dense core at the center of an atom

Question 12

Dalton

Answer 12

unit of measurement for atoms and subatomic particles mass, the same as atomic mass unit (AMU)

Question 13

Atomic Number

Answer 13

number of protons in an element, unique to each element

Question 14

Mass Number

Answer 14

number of protons and neutrons in the nucleus of an atom

Question 15

Isotopes

Answer 15

different atomic forms of the same element, even though they have slightly different masses, they behave identically in chemical reactions

Question 16

Radioactive Isotopes

Answer 16

isotopes of elements in which the nucleus spontaneously decays and gives off particles and energy, leading to a change in number of protons transforming into a different element

Question 17

Half-Life

Answer 17

a parent isotope decaying into a daughter isotope at a fixed rate, how long it takes 50% of the parent isotope to decay, not affected by temperature, pressure, or environment changes

Question 18

Radiometric Dating

Answer 18

measuring the ratio of different isotopes and calculating how many half-lives have passed since an organism was fossilized

Question 19

Energy

Answer 19

the capacity to cause change

Question 20

Potential Energy

Answer 20

energy that matter possesses due to its location or structure

Question 21

Electron Shells

Answer 21

where electrons are stored, concentric rings around the nucleus, first shell has 2 electrons and second shell can take up to 8, potential energy increases the more rings it has

Question 22

Valence Shell and Electron

Answer 22

the outer electron shell and all the elections found in the shell

Question 23

Inert

Answer 23

chemically unreactive

Question 24

Orbital

Answer 24

3D space where an electron is found 90% of the time, no more than 2 electrons can occupy the first orbital

Question 25

Chemical Bonds

Answer 25

covalent bonds in molecules and ionic bonds in compounds

Question 26

Covalent Bonds

Answer 26

the sharing of a pair of valence electrons by two atoms, two or more atoms held together by covalent bonds constitutes a molecule

Question 27

Electronegativity

Answer 27

the attraction of a particular atom for the electrons of a covalent bond, more electronegativity means stronger pull of electrons toward itself

Question 28

Nonpolar Covalent Bond

Answer 28

covalent bond between two atoms of the same element, the electrons are shared equally because they have the same electronegativity

Question 29

Polar Covalent Bond

Answer 29

when an atom is bonded to a more electronegative atom, vary in polarity depending on the electronegativity of the two

Question 30

Ions

Answer 30

two opposing charge atoms resulting from such an unequally attracted valence electron that the more electronegative atom strips an electron completely away from its partner

Question 31

Cation

Answer 31

positively charged ion

Question 32

Anion

Answer 32

negatively charged ion

Question 33

Ionic Bond

Answer 33

anion and cations attracted to each other due to their opposite charges, also known as salts, do not consist of molecules only indicates the ratio of elements in a crystal of salt

Question 34

Tetrahedron

Answer 34

pyramid with a triangular base, found when connecting the larger end of the teardrop shapes in a hybrid orbital model

Question 34

Van der Waal Interactions

Answer 34

ever changing regions of positive and negative charge that enable all atoms and molecules to stick to one another, individually weaker and only occur when atoms and molecules are very close together, become powerful when many bonds happen at once

Question 35

Chemical Reactions

Answer 35

the making and breaking of chemical bonds leading to changes on the composition of matter

Question 35

Endogenous

Answer 35

made by the body

Question 36

Reactants

Answer 36

starting materials in a conversion

Question 37

Products

Answer 37

the end resulting material in a conversion

Question 38

Chemical Equilibrium

Answer 38

when chemical reactions offset one another perfectly until the reaction comes to a standstill, equilibrium can fall to one side of a reaction that it is almost complete