Bio Module 1.B

e's are transferred completely from 1 atom to another, resulting in filled valence shells for both atoms; anion and cation are attracted to each other

Ionic bonds

substance that ionizes in solution to yield H+ and an anion; proton donor

acid

The cohesiveness between water molecules is due largely to: a. polar covalent bonds. b. ionic bonds. c. hydrophobic interactions. d. hydrogen bonds. e. nonpolar covalent bonds.

d. hydrogen bonds.

the amount of heat required to change the temperature of 1 g of a substance by 1O C

Specific heat

How many H-bonds can H2O form?

4

the attraction between H2O molecules and other charged molecules (e.g., glass)

Adhesion

attractive forces between atoms whose valence electrons interact to form a more stable chemical structure

Chemical bonds

atoms share e's to obtain a filled (stable) valence shell

Covalent bonds

Which of the following statements is FALSE? a. The 2nd energy level contains a maximum of 10 electrons. b. The 1st principal energy level contains 1 orbital. c. The 1st principal energy level contains a maximum of 2 electrons. d. The 2nd principal energy level contains 4 orbitals.

a. The 2nd energy level contains a maximum of 10 electrons.

Which characteristic of water makes the existence of pH possible? a. ionization b. polarity c. adhesion d. cohesion e. hydrophobicity

a. ionization

Which characteristic of water molecules directly contributes to the remarkable "water walking" success of the aquatic insects? a. hydrogen bonds b. adhesive forces c. capillary action d. nonpolar covalent bonds e. ionic bonds

a. hydrogen bonds

equal to the number of protons plus the number of neutrons in the nucleus of a single atom of that element

atomic mass

A pH of 4 is __________ times more __________ than a pH of 7. a. 1000; basic b. 1000; acidic c. 3; acidic d. 1000; neutral e. 3; basic

b. 1000; acidic

At what temperature is water most dense? a. 0 degrees Celsius b. 4 degrees Celsius c. 10 degrees Celsius d. 100 degrees Celsius e. 1 degree Celsius

b. 4 degrees Celsius

An atom that has eight electrons in its outermost shell is: a. not enough information is provided to answer the question b. non-reactive. c. extremelly reactive. d. fairly reactive.

b. non-reactive.

Which covalent bond involves only 2 electrons: a. single and triple. b. single c. triple d. single and double. e. double

b. single

It takes 1 calorie of heat to raise the temperature of 1 gram of water 1 degree Celsius at sea level. This is referred to as the __________ of water. a. heat of transformation b. specific heat c. heat of fusion d. heat of homeostasis e. heat of vaporization

b. specific heat

In electrically neutral atoms: a. the number of protons is equal to the nmber of neutrons b. the number of protons is equal to the number of electrons c. None of the above statements are true. d. the number of protons is less than the number of electrons

b. the number of protons is equal to the number of electrons

Table salt dissolves easily in water because: a. water can remove electrons from the chloride ion, which causes the latter to dissociate from the sodium and dissolve. b. the partial positive charge of the hydrogens in the water molecule can associate with the negative charge of the chloride ion, and the partial negative charge of the oxygen of the water molecule can associate with the positive charge of the sodium atom. c. water is polar and salt is nonpolar. Nonpolar compounds are more soluble in polar solvents because they are able to form strong covalent bonds that result in a breaking up of the molecule being dissolved. d. water can form covalent linkages with salt. e. water can add electrons to the sodium ion.

b. the partial positive charge of the hydrogens in the water molecule can associate with the negative charge of the chloride ion, and the partial negative charge of the oxygen of the water molecule can associate with the positive charge of the sodium atom.

The mass of a proton <?> the mass of a neutron a. the entity on the right is greater than that on the left. b. the two are approximately (or exactly) equal. c. the two can exist in more than one relationship to each other. d. the entity on the left is greater than that on the right.

b. the two are approximately (or exactly) equal.

substance that resists changes in pH when an acid or base is added

buffer

Which of the following statements is not correct? a. The amount of heat required to raise the temperature of 1 g of water 1 °C is one calorie. b. When one gram of water evaporates, it removes heat. c. Water heats up and cools down very quickly. d. Due to hydrogen bonds, water has a high surface tension. e. Large bodies of water have relatively constant temperatures.

c. Water heats up and cools down very quickly.

A salt is a compound in which the hydrogen ion of __________ is replaced by some other cation. a. a base b. an anion c. an acid d. a hydroxide ion e. water

c. an acid

An atom becomes a cation if: a. one or more of its electrons changes energy levels. b. it emits radiation. c. it loses one or more electron. d. it gains one or more electron. e. it shares electrons.

c. it loses one or more electron.

The chemical properties of an aton are determined primarily by the: a. size of its nucleus. b. number and arrangement of its neutrons. c. number and arrangement of its electrons. d. number and arrangement of its protons.

c. number and arrangement of its electrons.

How many molecules are present in one mole of C6H12O6? a. 24 molecules b. 1.7 ´ 10-10 molecules c. 1.3 ´ 1010 molecules d. 1.7 ´ 1022 molecules e. 6.02 ´ 1023 molecules

e. 6.02 ´ 1023 molecules

Water is an excellent solvent for many substances. Which of the following characteristic of water is most important in explaining it solvent characteristics? a. The expansion of water upon freezing b. The high specific heat of water. c. The adhesive quality of water molecules. d. The electric neutrality of water molecules. e. The polarity of individual water molecules.

e. The polarity of individual water molecules.

An element is defined as a substance that: a. is held together by covalent bonds. b. is composed of more than one kind of atom. c. is soluble in both acid and base. d. cannot burn. e. cannot be broken into simpler substances by chemical reactions.

e. cannot be broken into simpler substances by chemical reactions.

Which one of the following describes the relationship of the hypothetical atoms. Atom I: 4 protons 4 protons 4 protons Atom II: 4 neutrons 6 neutron 5 neutrons Atom III: 4 electron 4 electrons 4 elecrons They are: a. ions b. have different atomic numbers c. polymers d. isomers e. isotopes

e. isotopes

reflects an atom's attraction for e's in chemical bonds

electronegativity

chemical substances that can't be broken down into smaller units by ordinary chemical reactions

elements

compound in which the hydrogen ion of an acid is replaced by some other cation

salt

Are ionic compounds water-soluble?

yes

Are polar compounds water-soluble?

yes

the attraction between separate H2O molecules due to H-bonding

Cohesion

the amount of heat required to convert 1 g of a liquid to a gas (evaporation)

Heat of vaporization

has partially charged regions on polar molecules that are attracted to one another

Hydrogen bonds

have the same atomic number (# protons) but different atomic mass (because of a different # of neutrons)

Isotopes

equal to the number of protons in the nucleus of a single atom of that element

atomic number

proton acceptor

base

formed when 2 or more atoms share electrons in order to stabilize their valence shells

Molecules

smallest part of an element that retains its chemical properties and can enter into a chemical reaction

atom

unit pf measurement used in chemistry to express amounts of a chemical substance

mole

tells how many grams are required to make 1 mole

molecular weight of mass

Are nonpolar molecules water-soluble?

no

Which of the following are the four most common elements in living organisms? a. C,H,O,K b. C,H, O,Mg c. H,O,N,P d. C,H,O,N

d. C,H,O,N

The process whereby water molecules surround ions during the process of dissolving is called: a. vaporization. b. oxidation. c. reduction. d. hydration. e. buffering.

d. hydration.

The chemical behavior of an atom is determined by most directly by the: a. atomic weight. b. number of neutrons. c. number of energy levels. d. number of valence electrons. e. atomic number.

d. number of valence electrons.

different elements combine in a fixed ratio

chemical compound