Biology Chapter Two

Which of the following properties of water involve hydrogen bonds? Check all that apply

(A) cohesion (B) high heat capacity (C) surface tension (D) polarity (E) water expands as it freezes

The electron arrangement for argon, which has 18 electrons, is

2 in the inner electron shell, 8 in the second electron shell, and 8 in the outer electron shell.

The pH of pure water is ________ because ________.

7.0; water contains an equal number of H + ions and OH -ions

An element has an atomic number of 88. The number of protons and electrons in a neutral atom of the element are

88 protons and 88 electrons.

Of the following examples, which best demonstrates the property of water cohesion?

A rock skipping across the surface of a lake.

How does a strong acid differ from a weak acid?

A weak acid dissociates only partially in water.

Heartburn occurs when stomach acid escapes the stomach and burns the tissues of the esophagus. Baking soda is sometimes used as an antacid. How does baking soda help relieve symptoms of heartburn?

The baking soda is serving as a buffer to take up excess H + ions from stomach acid

Which of the following statements about atoms is correct?

The number and arrangement of electrons in an atom governs its chemical activity.

Which of the following best describes the structure of how water molecules form?

The oxygen atom and hydrogen atoms form a covalent bond with one another to create stable valence shells of electrons. The electrons are shared unequally resulting in a polar molecule.

Which of the following is a property of acids?

Acids have a sharp or sour taste.

Which of the following statements about basic solutions is true?

Basic solutions release OH -.

When a positively charged hydrogen in a water molecule become attracted to the negatively charged oxygen in a nearby water molecule, this is called a ionic bond.

False

Cola has a pH of 3.5. This means that it has an excess of _______ ions and would be called a(n) ________.

H +; acid

Which of the following would be an example of the value of water's heat capacity?

Living organisms are able to maintain their internal body temperatures because the water in their cells resists changes in temperature.

Which of the following is a molecule?

O 2

Both radioactive isotopes and stable isotopes contain the same number of electrons and protons.

True

In what ways are radioactive isotopes potentially harmful?

Unmonitored release into the environment can make changes in a cell's DNA.

Which of the following property of water helps an individual who is exercising vigorously maintain a constant body temperature?

Water has high heat capacity.

Which property of water causes sugar to dissolve in coffee?

Water is a good solvent.

An ionic bond forms when

a negatively charged ion is attracted to one with a positive charge.

Isotopes of an atom differ in their

atomic mass.

All atoms of the same element have the same

atomic number.

Glucose, C 6H 12O 6, is best described as a(n)

compound.

The pH scale is a mathematical indicator of the

concentration of H + present in a solution.

The figure below is depicting the interaction of water molecules with one another. The weak attractions between water molecules are known as

covalent bonds.

An atom's valence electron shell

determines its chemical reactivity.

An atom with a neutral charge has

equal numbers of protons and electrons.

Some insects can stride on the surface of water because water

has surface tension.

When water boils

hydrogen bonds are broken between neighboring water molecules.

The type of bond that would form from the transfer of an electron from one atom to another is a(n) ________ bond.

ionic

Cells need buffering agents in order to

minimize the changes in pH of their internal environment.

Isotopes of an element differ in their

neutron number

The subatomic particles that are found in the nucleus of an atom are the

neutrons and protons.

The atomic structure of water satisfies the octet rule by having

oxygen share electrons with two hydrogen atoms.

A covalent bond involves the sharing of

pairs of electrons.

In the reaction 6CO 2 + 6H 2O → C 6H 12O 6 + 6O 2 carbon dioxide is one of the

reactants.

The number of neutrons present in the nucleus of an average atom of any given element is best estimated by

subtracting the number of protons from the mass number.

Chemical bonds involve

the giving, taking, or sharing of electrons.

A water molecule, as shown here, is polar because of

unequal sharing of electrons.

The reactivity of an atom depends on the number of

valence electrons.