Brainscape's Knowledge GenomeTM

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


See full index

My Packs: AP Biology > (Unit 1) Chapter 2: Chemical Context of Life > Flashcards

(Unit 1) Chapter 2: Chemical Context of Life Flashcards

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

Define:

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
2
Q

Define:

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
3
Q

Define:

Trace Elements

A

Elements required by an organism in only minute quantities

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

Name elements making up about 96% of human body weight (Element, Symbol, Atomic Number, Percentage of Human Body Weight) (4)

A

Oxygen (O, 8), 65.0%
Carbon (C, 6), 18.5%
Hydrogen (H, 1), 9.5%
Nitrogen (N, 7), 3.3%

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

Name elements making up about 4% of human body weight (Element, Symbol, Atomic Number, Percentage of Human Body Weight) (7)

A 
Calcium (Ca, 20), 1.5%
Phosphorus (P, 15), 1.0%
Potassium (K, 19), 0.4%
Sulfur (S, 16), 0.3%
Sodium (Na, 11), 0.2%
Chlorine (Cl, 17), 0.2%
Magnesium (Mg, 12), 0.1%
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Name elements making up less than 0.01% of human body weight (Element, Symbol, Atomic Number) (

A 
Boron (B, 5)
Chromium (Cr, 25)
Cobalt (Co, 27)
Copper (Cu, 29)
Fluorine (F, 9)
Iodine (I, 53)
Iron (Fe, 26)
Manganese (Mn, 25)
Molybdenum (Mo, 42)
Selenium (Se, 34)
Silicon (Si, 14)
Tin (Sn, 50)
Vanadium (V, 23)
Zinc (Zn, 30)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the smallest unit of matter that still retains the properties of an element?

A

Atom

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

Atoms 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
9
Q

What three kinds of subatomic particles are relative in biology?

A

Neutrons, protons, and electrons

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

Protons and neutrons are packed together tightly in a dense core, or:

A

Atomic nucleus

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

True or False:

Protons and neutrons are very different in masses

A

False, neutrons and protons are almost identical in mass

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

How much do neutrons (and protons) weigh?

A

1.7 * 10^-24 gram

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

For atoms and subatomic particles (and molecules), what unit of measurement do we use?

A

Dalton

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

Who was the unit “dalton” named after?

A

John Dalton, the British scientist who helped develop atomic theory around 1800

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

The dalton is the same as the ______ ____ ____, or ___

A

Atomic mass unit

AMU

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

What is the mass of protons and neutrons?

A

Close to 1 dalton

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

True or False:

We can ignore electrons when computing the total mass of an atom

A

True, as the mass of the electron is just about 1/2000 that of a neutron or proton

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

Define:

Atomic number

A

The number of protons, which is unique to that element

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

Where is the atomic number written?

A

Written as a subscript to the left of the symbol of the element

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Define:

Mass number

A

The sum of protons and neutrons in the nucleus of an atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Where is the mass number written?

A

Written as a superscript to the left of an element symbol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Define:

Atomic mass

A

An approximation of the total mass of an atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Define:

Isotopes

A

The different atomic forms of an element with different masses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Define:

Radioactive isotope

A

An isotope where the nucleus decays spontaneously, giving off particles and energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Define:

Energy

A

The capacity to cause change - for instance, by doing work

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Where are radioactive tracers used? (2)

A

Diagnostic tools in medicine (e.x. diagnosing kidney disorders)
Used in imaging (PET scanners etc.)

27
Q

Define:

Potential energy

A

The energy that matter possesses because of its location or structure

28
Q

An electron’s energy level is correlated with its average ________ from the _______

A

Distance

Nucleus

29
Q

Electrons are found in different ________ ______, each with a characteristic average ________ and ______ level

A

Electron shells
Distance
Energy

30
Q

The chemical behaviour of an atom is determined by what?

A

Distribution of electrons in the atom’s electron shells; Mostly on the number of electrons in its outermost shell

31
Q

Define:

Valence electrons

A

Electrons in the outermost shell

32
Q

Define:

Valence shell

A

The outermost electron shell

33
Q

Define:

Inert

A

Chemically unreactive

34
Q

Which three elements in the first 18 elements are said to be inert?

A

Helium
Neon
Argon

35
Q

Define:

Orbital

A

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

36
Q

State the orbitals of the first electron shell

A

1 spherical s orbital (1s)

37
Q

State the orbitals of the second electron shell

A

1 spherical s orbital (2s)

3 dumbbell-shaped p orbitals (2p)

38
Q

No more than _ electrons can occupy a single orbital

A

2

39
Q

True or False:

When atoms interact in a way that completes their valence cells, paired electrons are involved

A

False, unpaired electrons are involved

40
Q

Define:

Chemical bonds

A

Attractions that hold atoms together when they share of transfer valence electrons

41
Q

Define:

Covalent bonds

A

The sharing of a pair of valence electrons by two atoms

42
Q

Two or more atoms held together by covalent bonds constitute what?

A

A molecule

43
Q

In the formula H-H, what does the line represent?

A

A single (covalent) bond (a pair of shared electrons)

44
Q

When the formula is written H : H, what type of diagram is this?

A

A Lewis Dot Diagram

45
Q

What type of notation is H-H?

A

Structural Formula

46
Q

What type of notation is H2?

A

Molecular Formula

47
Q

With O2, two pairs of electrons are shared between the two oxygen atoms, what type of bond is that?

A

A double (covalent) bond

48
Q

Define:

Valence

A

The bonding capacity of an atom

49
Q

What does an atom’s valence usually equal?

A

Usually equals the number of unpaired electrons required to complete the atom’s outermost (valence) shell

50
Q

Define:

Electronegativity

A

The attraction of a particular kind of atom for the electrons of a covalent bond (More electronegative = more strongly pulls shared electrons towards itself)

51
Q

What is the difference between a nonpolar covalent bond and a polar covalent bond?

A

When electrons are shared equally (usually between two atoms of the same element), it is a nonpolar covalent bond
When one atom is more electronegative than the other, the electrons of the bond are not shared equally and it creates a polar covalent bond

52
Q

Define:

Ionic bonds

A

The attraction between two atoms that are so unequal in electronegativity (more electronegative one strips electron away from the other, creating + and - attraction)

53
Q

Define:

Ion

A

A charged atom or molecule

54
Q

Define:

Cation

A

An ion with a positive charge

55
Q

Define:

Anion

A

An ion with a negative charge

56
Q

What are compounds formed by ionic bonds called?

A

Ionic compounds or Salts

57
Q

Define:

Hydrogen bonds

A

Forms when a hydrogen atom covalently bonded to one electronegative atom is also attracted to another electronegative atom

58
Q

Define:

Van der Waals Interactions

A

Ever-changing regions of positive and negative charge that enable all atoms and molecules to stick to one another

59
Q

Why do Van der Waals Interactions happen? When do they occur?

A

Electron are not always symmetrically distributed in a molecule and thus may accumulate by chance in one part of a molecule or another
Only occur when atoms and molecules are very close together

60
Q

What are molecular shapes determined by?

A

Determined by the positions of the atoms’ orbitals (e.x. Water molecules are roughly V-shaped with two covalent bonds spread apart at 104.5 degrees)

61
Q

Define:

Chemical reactions

A

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

62
Q

What are the starting materials in a chemical reaction called?

A

Reactants

63
Q

What are the reactants in a chemical reaction converted to?

A

Products

64
Q

Define:

Chemical equilibrium

A

The point at which the reactions offset one another exactly

My Packs: AP Biology (7 decks)

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