Biology: The Chemistry Context Of Life Ch.2

Front 1

There are _____ naturally occurring elements.

Back 1

92

Front 2

There are _____ naturally occurring elements.

Back 2

copper

Front 3

What is not one of the four most abundant elements found in living systems?

Back 3

zinc

Front 4

Which one of the following has negligible mass?

Back 4

electron

Front 5

Which one of the following subatomic particles has appreciable mass and lacks a charge?

Back 5

neutron

Front 6

The number of protons in an uncharged atom _____.

Back 6

equals the number of electrons

Front 7

Consider a hypothetical atom with an atomic number of 4 and a net electronic charge of +1. How many neutrons does this atom have? (Concept 2.2)

Back 7

The answer cannot be determined from the information provided.

Front 8

An element has 8 protons, 9 neutrons, and 8 electrons. Its atomic number and atomic mass, respectively, are _____.

Back 8

8 and 17

Front 9

Two atoms of the same element must have the same number of _____. (Concept 2.2)

Back 9

protons

Front 10

An uncharged atom of nitrogen (atomic number = 7) has _____. (Concept 2.2)

Back 10

An uncharged atom of nitrogen (atomic number = 7) has _____. (Concept 2.2)

Front 11

Isotopes of an element will always differ in _____. (Concept 2.2)

Back 11

atomic mass

Front 12

A particular carbon isotope has an atomic number of 6 and an atomic mass of 14. The respective number of neutrons, protons, and electrons that this carbon isotope has is _____. (Concept 2.2)

Back 12

8, 6, and 6

Front 13

Phosphorus-32 (radioactive) has _____ than phosphorus-35 (normal). (Concept 2.2)

Back 13

3 fewer neutrons

Front 14

The most common form of calcium has 20 protons, 20 neutrons, and 20 electrons. Which of the following elements would be an isotope of calcium? (Concept 2.2)

Back 14

an atom with 20 protons, 21 neutrons, and 20 electrons

Front 15

Which of the following is not a characteristic that makes radioactive tracers useful in medical diagnoses?

Back 15

They may damage or destroy molecules.

Front 16

Potassium (atomic number 19, mass number 40) and sodium (atomic number 11, mass number 23) have similar chemical properties and reactive behavior. This is because uncharged atoms of potassium and sodium _____. (Concept 2.2)

Back 16

have different mass numbers and each has 1 electron in its outermost electron shell

Front 17

Atomic chlorine has an atomic number of 17. It has _____ electrons in its third shell. (Concept 2.2)

Back 17

7

Front 18

The chemical characteristics or reactivity of an element depend mostly on the _____. (Concept 2.2)

Back 18

number of electrons in its outermost shell

Front 19

Some groups of elements react chemically in similar ways. For example, the chemistry of sodium and the chemistry of lithium are similar. The chemistry of chlorine and the chemistry of iodine are also similar. These similarities in chemistry result when different elements have similar _____. (Concept 2.2)

Back 19

numbers of outer-shell electrons

Front 20

How many electrons would be present in the valence shell of a sulfur atom (atomic number 16, mass number 32)? (Concept 2.2)

Back 20

6 electrons

Front 21

For most atoms, a stable configuration of electrons is attained when the atom _____. (Concept 2.2)

Back 21

has 8 electrons in its outermost shell

Front 22

An atom that normally has _____ in its outer shell would not tend to form chemical bonds with other atoms. (Concept 2.2)

Back 22

8 electrons

Front 23

A polar covalent bond is a bond that _____. (Concept 2.3)

Back 23

has shared electrons pulled closer to the more electronegative atom

Front 24

A covalent bond is likely to be polar if _____. (Concept 2.3)

Back 24

one of the atoms sharing electrons is much more electronegative

Front 25

When the proton number and electron number are unequal, the atom or molecule _____. (Concept 2.3)

Back 25

is an ion

Front 26

A sodium atom has a mass number of 23. Its atomic number is 11. How many electrons does it have if it is not an ion? (Concept 2.3)

Back 26

11

Front 27

Copper has an atomic number of 29 and a mass number of 64. What would result if an uncharged copper atom lost two electrons? (Concept 2.3)

Back 27

The atomic number would remain 29, the mass number would remain 64, and the atom would be a cation with a +2 charge.

Front 28

The compound CaSO4 ionizes into a calcium ion and a sulfate ion (SO4). Calcium has 2 electrons in its outer shell. Upon ionization, what would you expect the charge on the sulfate ion to be? (Concept 2.3)

Back 28

-2

Front 29

Ionic bonds form as a result of _____. (Concept 2.3

Back 29

attraction between atoms that have opposite charges

Front 30

A hydrogen bond _____. (Concept 2.3)

Back 30

is a weak chemical bond

Front 31

Which is not involved in, or is not relevant to, hydrogen bonding? (Concept 2.3)

Back 31

loss of electrons

Front 32

Hydrogen bonds occur when _____. (Concept 2.3

Back 32

partial opposite charges on molecules come close enough to attract each other

Front 33

Which of the following molecules has the shape of a completed tetrahedron? (Concept 2.3)

Back 33

methane (CH4)

Front 34

Which of the following statements is not true about chemical reactions? (Concept 2.4)

Back 34

They represent the way matter is created and destroyed.

Front 35

Which one of the following does the equation of a chemical reaction not tell us? (Concept 2.4)

Back 35

the speed of the reaction

Front 36

Which of the following statements describes a reversible reaction that has reached chemical equilibrium? (Concept 2.4)

Back 36

The rate of the reverse reaction equals the rate of the forward reaction.

Front 37

Matter

Back 37

anything that take up space and has mass.

Front 38

electronegatively

Back 38

the attractions of an atom for the electron of a covalent bond

Front 39

element

Back 39

any substance that cannot be broken down into any other substance

Front 40

compound

Back 40

a substance consist of two or more elements in a fixed ratio

Front 41

potential energy

Back 41

the energy stored by matter as a result of its location or spatial arrangement

Front 42

ionic bond

Back 42

chemical bonds that is attraction between oppositly charged ion

Front 43

atomic nucleous

Back 43

an atom's central core, containing proton and neutron

Front 44

neutron

Back 44

an electrically neutral particle (have no charge), found in the atomic nucleous

Front 45

chemical bond

Back 45

the attraction between two atoms, resulting from sharing of outer-shell electrons

Front 46

energy level

Back 46

any of several different states of potential energy in an atom

Front 47

nonpolar covalent bond

Back 47

a type of convalent bond between electrons are shared equally between two atoms of a similar electronnegatively

Front 48

hydrogen bond

Back 48

a type of weak chemical bond formed which the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted the the slightly negative atom of a polar covalent bond in another molecule

Front 49

atom number

Back 49

the number of protons in the nucleous of an atom, unique for each element and designated by a subacript to the left of the element symbol

Front 50

ion

Back 50

an atom that has gain or lost electron, needs to be charged