A&P Chapter 2 Homework

An element has an atomic number of 17 and a mass of 35. How many protons, neutrons, and electrons does the element have?

17 protons, 18 neutrons, and 17 electrons

If atom X has an atomic number of 74 it would have which of the following?

74 protons

Select the statement about mixtures that is correct.

A solution contains solvent in large amounts and solute in smaller quantities.

Which of the following is true of atomic weight?

Atomic weight of an element is approximately equal to the mass number of its most abundant isotope.

Which four elements comprise approximately 96% of body weight?

Carbon, oxygen, hydrogen, and nitrogen.

Chemical properties are determined primarily by neutrons.

False

Covalent bonds are generally less stable than ionic bonds.

False

Hydrogen bonds are comparatively strong bonds.

False

Isotopes differ from each other only in the number of electrons contained.

False

Select the correct statement about isotopes.

Isotopes of the same element have the same atomic number but differ in their atomic masses.

What is the difference between kinetic and potential energy?

Kinetic energy is energy in action, while potential energy is stored energy.

What of the following is not a difference between a compound and a mixture:

Mixtures are homogeneous while compounds are heterogeneous.

Which of the following best describes an isotope?

Structurally variant atoms, which have the same number of protons (and electrons), but differ in the number of neutrons they contain.

Which of the following best defines covalent bonds?

The bond formed when shared electrons occupy a single orbital common to both atoms within a molecule.

Which of the following is true regarding the pH of a solution?

The more hydrogen ions in a solution, the more acidic the solution is.

What does CH4 mean?

There is one carbon and four hydrogen atoms.

What are the two fundamental roles of DNA?

To direct protein synthesis, and replicate itself before cell division.

A charged particle is generally called an ion.

True

A molecule consisting of one carbon atom and two oxygen atoms is correctly written as CO2.

True

All organic compounds contain carbon.

True

Buffers help to stabilize blood pH.

True

Buffers resist abrupt and large changes in the pH of the body by releasing or binding ions.

True

Emulsions and colloids are the same thing.

True

Mixtures are combinations of elements or compounds that are physically blended together but are not bound by chemical bonds.

True

No chemical bonding occurs between the components of a mixture.

True

The atomic weight is only an average of relative weights of an atom and its isotopes, and it may vary from the weight of a specific isotope.

True

The fact that no chemical bonding occurs between the components of a mixture is the chief difference between mixtures and compounds.

True

The lower the pH, the higher the hydrogen ion concentration.

True

The pH of body fluids must remain fairly constant for the body to maintain homeostasis.

True

What is a dipole?

a polar molecule

A solution that has a pH of 2 could best be described as being ________.

acidic

What is the classification of a solution with a pH of 8.3?

alkaline solution

Water:

can form hydrogen bonds.

In liquid XYZ, you notice that light is scattered as it passes through. There is no precipitant in the bottom of the beaker, though it has been sitting for several days. What type of liquid is this?

colloid

Two good examples of a colloid would be Jell-O® and ________.

cytosol

Which property of water is demonstrated when we sweat?

high heat of vaporization

Salts are always ________.

ionic compounds

The pH scale:

is based on the concentration of H+ ions.

Which of the following is NOT a compound?

oxygen gas

Which of the following is the major positive ion outside cells?

sodium

What is the most abundant and important inorganic compound in living material?

water