Chapter 2- The Chemical Context of Life Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

half-life

A

the amount of time it takes for 50% of a sample of a radioactive isotope to decay.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

van der Waals interactions

A

Weak attractions between molecules or parts of molecules that result from transient local partial charges.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

anion

A

negatively charged ion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

reactant

A

the starting material in a chemical reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

chemical reaction

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

chemical bond

A

an attraction between two atoms, resulting from a sharing of outer-shell electrons or the presence of opposite charges on the atoms. The bonded atoms gain complete outer shells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

compound

A

a substance consisting of two or more different elements combined in a fixed ratio.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

ionic compound

A

a compound resulting from the formation of an ionic bond; also called a salt

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

cation

A

positively charged ion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

chemical equilibrium

A

In a chemical reaction, the state in which the rate of the forward reaction equals the rate of the reverse reaction, so that the relative concentrations of the reactants and products do not change with time.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

radioactive isotope

A

an isotope that is unstable; the nucleus decays spontaneously, giving off detectable particles and energy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Molar Solutions

A

1 mol
___________ = 1 MOLAR (M) in concentration
1 liter of water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Brownian Motion

A

Molecules always moving.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

ice

A

Stabilizes a lattice (molecules are further apart- ALL the H bonds are created)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

cohesion

A

molecules interacting with the same molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

solutes

A

substance that is dissolved

17
Q

solvent

A

dissolving agent

18
Q

solution

A

homogenous liquid mixture

19
Q

hydrophillic

A

dipole

20
Q

hydrophobic

A

nonpolar

21
Q

amphiphilic / amphipathic

A

molecules having polar water-soluble group attached to water-insoluble group

22
Q

transient dipole

A

stabilized by molecules next to each other

23
Q

hydrophobic effect

A

non-interaction of H bonds with water and van de Waals-interactions of the hydrophobic substance

24
Q

acid

A

any substance that when added to water raises the concentration of H+

25
Q

base

A

any substance that when added to water reduces the concentration of H+, often raising the OH-

26
Q

Strong vs Weak acids/bases

A

a STRONG acid/base dissociates completely in water

a WEAK acid/base varies in their degree of dissociation

27
Q

buffers

A
  • substances that RESIST a change in pH.
  • weak acids and weak bases = buffers
  • they maintain a relatively constant pH by absorbing or releasing [H+]
28
Q

uncharged atom

A

equal number of protons and electrons

29
Q

unreactive / inert

A

an atom with a complete valence shell

30
Q

the reactivity of an atom arises from

A

the existance of unpaired electrons in the valence shell.

31
Q

unstable isotopes

A
  • nucleus decays spontaneously
  • radioactive
  • can be transformed into an atom of another element
32
Q

decay

A
  • losing subatomic particles

- likely to occur when an atom has too many neutrons