Chapter 2

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

\(\mathrm{A}(\mathrm{n})\) ______ substance repels water. a. acidic b. basic c. hydrophobic d. polar

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

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

\(\mathrm{A}(\mathrm{n}) \) ________ can help keep the \(\mathrm{pH}\) 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. ______ hydrophilic ______ atomic number ______ hydrogen bonds ______ positive charge ______ temperature ______ negative charge a. protons \(>\) electrons b. number of protons in nucleus c. polar; dissolves easily in water d. collectively strong e. protons \(<\) electrons f. measure of molecular motion