Question

1. complete the electron - dot structures below to show how beryllium fluoride (bef₂) is formed. use the diagram on page 203 as a model.

be + f → be f f

1. most ionic compounds are solid at room temperature.

1. is the following sentence true or false? ionic compounds generally have low melting points. false

1. circle the letter of each statement that is true about ionic compounds.

a. when dissolved in water, ionic compounds can conduct electricity.
b. when melted, ionic compounds do not conduct electricity.
c. ionic compounds have very unstable structures.
d. ionic compounds are electrically neutral.

Explanation:

Step1: Recall ionic - compound properties

Ionic compounds are formed by the transfer of electrons between a metal and a non - metal. Beryllium (Be) is a metal and fluorine (F) is a non - metal.

Step2: Analyze question 5

Most ionic compounds are solid at room temperature due to the strong electrostatic forces between ions.

Step3: Analyze question 6

Ionic compounds generally have high melting points because of the strong ionic bonds holding the ions together. So the statement "Ionic compounds generally have low melting points" is false.

Step4: Analyze question 7

• a. When dissolved in water, ionic compounds dissociate into ions which can conduct electricity. This is true.
• b. When melted, ionic compounds also dissociate into ions and can conduct electricity. So the statement "When melted, ionic compounds do not conduct electricity" is false.
• c. Ionic compounds have very stable structures due to the strong electrostatic forces between oppositely charged ions. So the statement "Ionic compounds have very unstable structures" is false.
• d. Ionic compounds are electrically neutral because the total positive charge of the cations equals the total negative charge of the anions. This is true.

Answer:

1. solid
2. false
3. a. True, d. True