CH2: THE CHEMICAL CONTEXT OF LIFE

Question 1

anything that takes up space and has mass; made up of elements

Answer 1

Matter

Question 2

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

Answer 2

Element

Question 3

a substance consisting of two or more different elements combined in a fixed ratio; has characteristics different from those of its elements (emergent properties)

Answer 3

Compound

Question 4

elements an organism needs to live a healthy life and reproduce (20-25% of 92 elements)

Answer 4

Essential Elements

Question 5

required by an organism in only minute quantities.

Answer 5

Trace Elements

Question 6

substances that if you interact with it in a certain way can kill or harm

Answer 6

Toxins

Question 7

a toxin you ingest

Answer 7

Poison

Question 8

when another organism intentionally bites you

Answer 8

Venom

Question 9

the smallest unit of matter than still retains the properties of an element; made of subatomic particles

Answer 9

Atom

Question 10

make up atoms

Answer 10

Subatomic Particles

Question 11

Name the 3 Subatomic Particles

Answer 11

Neutrons
Protons (large)
Electrons (small)

Question 12

center of an atom where protons and neutrons are packed together tightly

Answer 12

Atomic Nucleus

Question 13

Where are the electrons in relation to the atomic nucleus

Answer 13

electrons form an electron cloud (caused by rapid movement) around the nucleus

Question 14

the unit of measure for atoms and subatomic particles

Answer 14

Daltons

Question 15

the number of protons in the nuclei of an element (left subscript)

Answer 15

Atomic Number

Question 16

protons + neutrons in the nucleus of an atom (left superscript)

Answer 16

Mass Number

Question 17

the approximation of the total mass of an atom

Answer 17

Atomic Mass

Question 18

the different atomic forms of the same element (different number of neutrons, so different weights); different masses but chemically identical

Answer 18

Isotopes

Question 19

isotopes that their nuclei do not have a tendency to lose subatomic particles

Answer 19

Stable Isotopes

Question 20

one in which the nucleus decays spontaneously, giving off particles and energy

Answer 20

Radioactive Isotope

Question 21

can track atoms through metabolism

Answer 21

Radioactive Tracers

Question 22

the time it takes for 50% of the parent isotope to decay into its daughter isotope at a fixed rate

Answer 22

Half-Life

Question 23

scientists measure the ratio of different isotopes and calculate how many half-lives have passed since the fossil or rock was formed

Answer 23

Radiometric Dating

Question 24

the capacity to cause change (i.e. doing work)

Answer 24

Energy

Question 25

the energy that matter possess because of its location or structure

Answer 25

Potential Energy

Question 26

where electrons are found, each ______ has a characteristic average distance and energy level

Answer 26

Electron Shell

Question 27

Electrons CLOSE to nucleus = ______ potential energy

Answer 27

less

Question 28

Electrons FARTHER from nucleus = ______ potential energy

Answer 28

more

Question 29

outermost electron shell

Answer 29

Valence Shell

Question 30

Outermost electrons

Answer 30

Valence Electrons

Question 31

chemically unreactive (atoms with completed valence shells)

Answer 31

inert

Question 32

Elements react based on their _________

Answer 32

electrons (in their valence shell)

Question 33

three-dimensional space where an electron is found 90% of the time (1s, 2s, 2p, 3s...); not really cloud, more of a specific shape

Answer 33

Orbital

Question 34

the attractions that hold atoms close together when they interact

Answer 34

Chemical Bonds

Question 35

the SHARING of a pair of valence electrons by two atoms

Answer 35

Covalent Bond

Question 36

are made up of two or more atoms held together by covalent bonds

Answer 36

Molecule

Question 37

represents molecules (i.e. H2)

Answer 37

Molecular Formula

Question 38

H:H

Answer 38

Lewis Dot Structure

Question 39

H--H

Answer 39

Structural Formula

Question 40

the attraction of a particular atom for the elctrons of a covalent bond (more _________ = partial negative)

Answer 40

Electronegativity

Question 41

electrons are shared equally in covalent bonds because the two atoms have the same electronegativity

Answer 41

Nonpolar Covalent

Question 42

an atom is bonded to a more electronegative atom, the electrons of the bond are not shared equally (partial negatives and partial positives)

Answer 42

Polar Covalent

Question 43

bond formed by the attraction of a cation and anion; one donates/transfers electron to another give away electron = more positive (cation) gains electron = more negative (anion)

Answer 43

Ionic Bond

Question 44

charged atoms or molecules

Answer 44

Ions

Question 45

compounds formed by ionic bonds (found in crystals)

Answer 45

Ionic Compounds or Salts

Question 46

attraction between a hydrogen and an electronegative atom

Answer 46

Hydrogen Bonds

Question 47

when atoms and molecules are very close together because electrons may not be evenly distributed

Answer 47

Van der Waals Interactions

Question 48

the making and breaking of chemical bonds, leading to changes in the composition of matter; reversible

Answer 48

Chemical Reactions

Question 49

the point at which the reactions offset one another exactly; rxn still happening but with no net effect on the concentrations of reactants and products (stabilized concentrations at a particular ratio)

Answer 49

Chemical Equilibrium

Question 50

father of the periodic table

Answer 50

Dmitri Ivanovich Mendeleev

Question 51

proposed a model of the atom in which the electron was able to occupy only certain orbits around the nucleus

Answer 51

Neils Bohr