Physical Science Chapter 6

Typically, atoms gain or lose electrons to achieve

• an exchange of energy.
• ionization.
• a stable electron configuration.
• vaporization

In an electron dot diagram, the symbol for an element is used to represent

• the nucleus
• the nucleus and all electrons
• the nucleus and all valence electrons
• the nucleus and all non-valence electrons

Study the electron dot diagrams for lithium, carbon, fluorine, and neon in the figure. Choose the statement that correctly identifies the most stable of the elements.

• Lithium is the most stable element because it has to lose only one electron to achieve a stable configuration.
• Carbon is the most stable element because it can form four bonds.
• Fluorine is the most stable element because it has to gain only one electron to achieve a stable configuration.
• Neon is the most stable element because its highest occupied energy level is filled.

Ionization energies tend to

• decrease from left to right across a period.
• increase from the top of a group to the bottom.
• increase from left to right across a period.
• decrease from the bottom of a group to the top.

The formation of an ionic bond involves the

• transfer of electrons
• transfer of neutrons
• transfer of protons
• sharing of electrons

Which of the following statements correctly describes the substance with the formula KI?

• Molecules of potassium iodide contain one atom of potassium and one atom of iodide.
• There is a one-to-one ratio of potassium ions to iodide ions.
• Potassium iodide is a molecular compound.
• Potassium iodide is a polyatomic ion.

In the compound MgCl₂, the subscript 2 indicates that

• there are two magnesium ions for each ion of chlorine
• the chloride ion is twice the size of the magnesium ion.
• magnesium and chlorine form a double covalent bond.
• there are two chloride ions for each magnesium ion.

Which of the following is a typical property of an ionic compound?

• low melting point
• poor conductor of electric current when melted
• tendency to shatter when struck
• all of the above

You see a structural formula in which the symbols for elements are connected by a long dash. You can assume that the chemical bonds in the compound are

• ionic
• covalent
• metallic
• unstable

Which of the following formulas represents a compound whose molecules contain a triple bond?

• N≡N

• O=O=O

• O₃

• SO₃