Chemistry Final Review

How do ions combine to create electrically neutral compounds? (DoK Level 2)

• By balancing the total positive and negative charges

• By sharing all their electrons

• By splitting into smaller ions

• By losing all their protons

Which of the following is NOT a correct step in drawing Lewis structures?

• Count total valence electrons

• Create bonding framework

• Distribute protons among atoms

• Distribute remaining electrons

Which of the following is a common covalent molecule?

• Sodium Chloride (NaCl)

• Water (H₂O)

• Calcium Carbonate (CaCO₃)

• Potassium Iodide (KI)

Why is understanding periodic trends important in chemistry?

• It helps predict the melting point of elements

• It helps predict bonding behavior

• It helps determine the color of compounds

• It helps calculate atomic mass

Sometimes the bonds within a molecule are polar, but the molecule itself is non-polar. What property of the molecule allows this to happen?

• The molecule has a symmetrical shape

• The molecule contains only one type of atom

• The molecule is always ionic

• The molecule has a high electronegativity difference

How can you determine if a molecule is nonpolar?

• Check if the molecule is equal on all sides and has a symmetrical shape

• Check if the molecule contains only metals

• Check if the molecule has a high electronegativity difference

• Check if the molecule is a gas at room temperature

Which of the following best describes a polar molecule?

• The molecule is not equal on all sides and has an asymmetrical shape

• The molecule is equal on all sides and has a symmetrical shape

• The molecule contains only nonmetals

• The molecule has no bonds

Which of the following best describes a polar molecule?

• A molecule with equal sharing of electrons between atoms

• A molecule with unequal sharing of electrons between atoms

• A molecule with no electrons

• A molecule with only one type of atom

What is the main difference between a polar and a non-polar molecule?

• Polar molecules have equal sharing of electrons, non-polar have unequal sharing

• Polar molecules have unequal sharing of electrons, non-polar have equal sharing

• Both have equal sharing of electrons

• Both have unequal sharing of electrons

Which of the following molecules is non-polar due to its symmetry?

• HCl

• Chloroborane (BH2Cl)

• Borane (BH3)

• H2O