UNIT 2 EXAM REVIEW

Which of the following scientific claims about the bond in the molecular compound HF is most likely to be true?

• There is a partial negative charge on the H

  H atom.

• Electrons are shared equally between the H

  H and F atoms.

• The bond is highly polar.

Typically, metals are both malleable and ductile. The best explanation for these properties is that the electrons involved in bonding among metal atoms are

• unequally shared and form nondirectional bonds

• unequally shared and form highly directional bonds

• equally shared and form nondirectional bonds

Tags

NGSS.HS-PS1-1

The elements and have the same electronegativity value, 2.55. Which of the following claims about the compound that forms from and is most likely to be true?

• The carbon-to-selenium bond is unstable.

• The carbon-to-selenium bond is nonpolar covalent.

• The compound has the empirical formula .

Two pure elements react to form a compound. One element is an alkali metal, and the other element is a halogen. Which of the following is the most valid scientific claim that can be made about the compound?

• It has the formula XZ₂

• It does not dissolve in water.

• It contains ionic bonds.

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Which of the following correctly indicates whether the solid represented by the particulate model shown above conducts electricity and explains why or why not?

• It conducts electricity because it is made of positive and negative ions.

• It conducts electricity because it is made of particles of different sizes.

• It does not conduct electricity because its ions cannot move freely within the solid

Tags

NGSS.HS-PS1-3

On the basis of Coulomb’s law, which of the following best helps to explain the large difference between the lattice energies of NaF and MgF2

• The electronegativity of Mg is greater than that of Na.

• The mass of the cation Mg is greater than that of the cation Na.

• The charge of the cation Mg is larger than that of the cation Na.

Tags

NGSS.HS-PS2-4

The phenomenon shown in the diagram best supports which of the following claims about the bonding in C₆H₆ ?

• In the C6H6 molecule, all the bonds between the carbon atoms have the same length.

• A Because of variable bonding between its carbon atoms, C6H6C6H6 is a good conductor of electricity.

• The bonds between carbon atoms in C6H6 are unstable, and the compound decomposes quickly.

Tags

NGSS.HS-PS1-2

Which of the following Lewis diagrams best represents the bonding in the N₂O molecule, considering formal charges?

• A

• B

• C

• D

Tags

NGSS.HS-PS1-2

Which of the following statements, if true, would support the claim that the NO3− ion, represented above, has three resonance structures?

• The NO3− ion is not a polar species.

• The oxygen-to-nitrogen-to-oxygen bond angles are 90°

• One of the bonds in NO3− is longer than the other two.

Tags

NGSS.HS-PS1-2

Which of the following claims about the molecules is best supported by the diagrams?

• All the molecules have the same empirical formula.

• The strongest carbon-to-carbon bond occurs in molecule 3.

• The C-C-C bond angle in molecule 2 is close to 180°.