Chemistry 3 Common Unit Assessment Items

A group of students are trying to design an electrical material. The models are options of substances that the students could use. Model A Model B Model C Which substances should the students use if they are trying to design an electrically conductive material?

• A. Models A and B because the majority of materials on Earth are made of these.

• B. Models A and C because they contain ions so they can conduct electricity.

• C. Models B and C because gases and metals can conduct electricity.

• D. Models A, B, and C because all compounds can conduct electricity.

Which of the following explanations correctly describes the materials?

• A. Plastic polymers used in bottles are short molecules that create a non-flexible structure.

• B. Plastic polymers used in bottles are long molecules that create a very flexible structure.

• C. Calcium carbonate is a short molecule that creates a very flexible structure.

• D. Calcium carbonate is a long molecule that creates a non-flexible structure.

An engineer is developing a new material that would allow electricity to flow. Which of the following materials would an engineer choose and why?

• A. Carbon, because it is a good insulator.

• B. Copper, because it is a good insulator.

• C. Carbon, because it contains ions that have the ability to conduct electricity.

• D. Copper, because it contains ions that have the ability to conduct electricity.

Use the data table to answer the following question. Element Electronegativity X 1.61 Y 3.16 What type of bond would be formed between hypothetical elements X and Y in the compound XY based on their electronegativity difference?

• A. Nonpolar covalent because the difference in electronegativity is greater than 1.7.

• B. Nonpolar covalent because the difference in electronegativity is greater than 0.4, but less than 1.7.

• C. Polar covalent because the difference in electronegativity is greater than 0.4, but less than 1.7.

• D. Ionic because the difference in electronegativity is greater than 0.4, but less than 1.7.

Which group of nonmetals will react with Group 1 metals to form a compound in a one-to-one ratio?

• A. Group 15

• B. Group 16

• C. Group 17

• D. Group 18

Use the periodic table for the following question. What type of bond would you predict to be formed between new elements located at the bottom of columns E and G?

• A. Ionic, because element E is a metal and bonds with G, a nonmetal, to combine in a 1:1 ratio.

• B. Ionic, because element E is a metal and bonds with G, a nonmetal, to combine in a 1:7 ratio.

• C. Nonpolar covalent because element E is a metal and bonds with G, a nonmetal, to combine in a 1:1 ratio.

• D. Nonpolar covalent because element E is a metal and bonds with G, a nonmetal, to combine in a 1:7 ratio.

Use the information and models to answer the following question. The models show different types of bonding. Which model represents the diatomic molecule F2?

• A. Model A, because it shows charged particles from transferring electrons between the Fluorine atoms.

• B. Models A and C, because it is a charged particle so the bonding shows fluorine with a negatively charged anion.

• C. Model B, because it is an equal sharing of electrons since fluorine has an electronegativity difference of zero.

• D. Model C, because it shows a sharing of electrons by making an anion and cation which allows Fluorine to bond with each other.

Use the models to answer the following question. Which model represents a nonpolar molecule?

• A. Model A, because there is a transfer of electrons.

• B. Model B, because there is a transfer of electrons.

• C. Model A, because there is an equal sharing of electrons.

• D. Model B, because there is an equal sharing of electrons.

Use the models to answer the following question. Which model represents an ionic compound?

• A. Model A, because there is a transfer of electrons resulting in a cation and anion.

• B. Model A, because there is an unequal sharing of electrons resulting in partial positive and partial negative charges.

• C. Model B, because there is a transfer of electrons resulting in a cation and anion.

• D. Model B, because there is an unequal sharing of electrons resulting in partial positive and partial negative charges.

Use the table to answer the following question. Element Electronegativity Lithium 0.98 Nitrogen 3.04 How does the electronegativity of lithium (Li) compare with that of nitrogen (N)?

• A. These two elements would most likely form an ionic bond by sharing electrons.

• B. These two elements would most likely form a covalent bond by sharing electrons.

• C. These two elements would most likely form an ionic bond by transferring electrons.

• D. These two elements would most likely form a covalent bond by transferring electrons.