9th Grade Physical Science Ch. 6 Test

Which of the following groups contain three elements with stable electron configurations?

• lithium, krypton, argon

• argon, neon, barium

• xenon, neon, boron

• helium, xenon, neon

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 valence electrons

• the nucleus and all non-valence electrons

Study the electron dot diagrams for lithium, carbon, fluorine, and neon in Figure 6-1. 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?                               

 $K_{ }^+\ \ \ I^-$  

• Molecules of potassium iodide contain one atom of potassium and one atom of iodine

• 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  $MgCl_2$  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 statement best describes the properties of sodium chloride?

• Sodium chloride is a malleable solid

• Solid sodium chloride is a good conductor of electric current

• Sodium chloride has a low melting point

• Liquid sodium chloride is a good conductor of electric current

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