Chapter 2

What atom has only one proton? a. hydrogen b. an isotope c. a free radical d. a radioisotope

A molecule into which a radioisotope has been incorporated can be used as a(n) _________. a. compound b. tracer c. salt d. acid

Which of the following statements is incorrect? a. Isotopes have the same atomic number and different mass numbers. b. Atoms have about the same number of electrons as protons. c. All ions are atoms. d. Free radicals are dangerous because they emit energy.

In the periodic table, symbols for the elements are arranged according to _______. a. size b. charge c. mass number d. atomic number

An ion is an atom that has ________. a. the same number of electrons and protons b. a different number of electrons and protons c. electrons, protons, and neutrons

The measure of an atom's ability to pull electrons away from another atom is called _______. a. electronegativity b. charge c. polarity

The mutual attraction of opposite charges holds atoms together as molecules in a(n) _______ bond. a. ionic b. hydrogen c. polar covalent d. nonpolar covalent

Atoms share electrons unequally in a(n) _______ bond. a. ionic b. hydrogen c. polar covalent d. nonpolar covalent

A(n) _______ substance repels water. a. acidic b. basic c. hydrophobic d. polar

A salt does not release _______ in water. a. ions b. energy c. \(\mathrm{H}^{+}\)

Hydrogen ions \(\left(\mathrm{H}^{+}\right)\) are ________. a. in blood b. protons c. indicated by a pH scale d. all of the above

When dissolved in water, a(n) _______ donates \(\mathrm{H}^{+}\); a(n) ______ accepts \(\mathrm{H}^{+}\). a. acid; base b. base; acid c. buffer; solute d. base; buffer

A _______ can help keep the pH of a solution stable. a. covalent bond b. hydrogen bond c. buffer d. \(\mathrm{pH}\)

A _______ is dissolved in a solvent. a. molecule b. solute c. salt

Match the terms with their most suitable description. $$ \text {________hydrophilic} \quad \quad\quad\quad\quad \text {a. protons > electrons} $$ $$ \text {________atomic number} \quad \quad\quad\quad\quad \text {b. number of protons in nucleus} $$ $$ \text {________hydrogen bonds} \quad \quad\quad\quad\quad \text {c. polar; dissolves easily in water} $$ $$ \text {________positive charge} \quad \quad\quad\quad\quad \text {d. collectively strong} $$ $$ \text {________temperature} \quad \quad\quad\quad\quad \text {e. protons \(<\) electrons} $$ $$ \text {________negative charge} \quad \quad\quad\quad\quad \text {f. measure of molecular motion} $$