Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology 121 > Chapter 2 > Flashcards

Chapter 2 Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Organisms are composed of matter, which is:

A

Anything that takes up space and has mass.

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

An element:

A

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

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

Matter is made up of…

A

Elements

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

How many elements are recognized in nature by chemists today?

A

92

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

A compound is:

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
6
Q

How much of the 92 natural elements are essential for a healthy life and reproduction?

A

20 to 25%

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

Trace elements:

A

Required by an organism in only minute quantities

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

Atoms:

A

The smallest unit of matter that still retains the properties of an element.

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

Adams are composed of even smaller parts called:

A

Subatomic particles

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

Each proton has one unit of…

A

Positive charge

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

Each electron has one unit of…

A

Negative charge

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

Atomic number

A

The number of protons in the nucleus of a particular element.
Written as a subscript to the left of the symbol for the element.

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

Mass number:

A

The number of protons and neutrons in the nucleus of an atom.
Written as a subscript to the left of an element symbol.

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

The number of neutrons in the nucleus of an atom can be determined by:

A

Subtracting the atomic number from the mass number

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

Isotopes

A

Different atomic forms of the same element.

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

Stable isotopes

A

Nuclei do not have a tendency to lose it subatomic particles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Radioactive isotope

A

Nucleus decays spontaneously, giving off particles and energy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Half-life of the isotope:

A

The time it takes for 50% of the parent isotope to decay.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Energy is defined as:

A

The capacity to cause change

20
Q

Potential energy

A

The energy that matter possesses because of its location or structure

21
Q

Matter has a natural tendency to move toward the…

A

Lowest possible state of potential energy

22
Q

Electrons have potential energy due to their…

A

Distance from the nucleus

23
Q

The more distant an electron is from the nucleus, the…

A

greater its potential energy.

24
Q

And electrons potential energy is determined by…

A

Its energy level.

And electron can only exit at certain energy levels, not between them.

25
Q

An electron can move from one shell to another, but only by…

A

Absorbing or losing an amount of energy equal to the difference in potential energy between its position in the old shell and that in the new shell.

26
Q

When an electron absorbs energy:

A

It moves to a shell farther out from the nucleus

27
Q

When an electron loses energy:

A

It falls back to a show closer to the nucleus, lost energy is usually released to the environment as heat.

28
Q

The chemical behavior of an Atom depends mostly on:

A

The number of electrons in its outer most shell

29
Q

Valance electrons

A

Electrons in the outer shell

30
Q

Valance shell

A

The outer most electron shell

31
Q

Atoms with the same number of electrons in their valance shells…

A

Exhibit similar chemical behavior

32
Q

And atom with a completed valance shell is:

A

Unreactive; will not interact readily with other atoms

33
Q

Inert

A

Chemically unreactive

34
Q

Orbital

A

The three-dimensional space where an electron is found 90% of the time

35
Q

Covalent bond

A

Sharing of a pair of balance electrons by two atoms

36
Q

Two or more atoms how together by covalent bonds constitute a…

A

Molecule

37
Q

Compound

A

A combination of two or more different elements

38
Q

Electronegativity

A

The attraction of a particular Atom for the electrons of a covalent bond.

39
Q

A nonpolar covalent bond

A

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

40
Q

A polar covalent bond

A

When an atom is bonded to a more electronegative atom. Electrons are not shared equally.

41
Q

Ions

A

The two resulting oppositely charged atom or molecules. Two atoms are so an equal in their attraction for a valance electron is that the more electronegative atom strips an electron completely away from his partner.

42
Q

A positively charged ion is called

A

An cation

43
Q

A negatively charged ion is called

A

An anion

44
Q

An ionic bond

A

Is formed due to the opposite charges, cations and anions which attract each other.

45
Q

Hydrogen bond

A

Hydrogen atom is covalently bonded to a electron negative atom, the hydrogen atom has a partial positive charge that allows it to be attracted to a different electronegative atom nearby.

46
Q

In living cells, the electronegative partners of the partially positive charged hydrogen atom are usually:

A

Oxygen or nitrogen atoms

Biology 121 (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions