Lewis Electron Dot Formulas and Octet Rule Quiz

What does the Roman numeral in the group label indicate in the context of Lewis electron dot formulas?

• The atomic number of the element

• The number of valence electrons

• The number of protons

• The number of neutrons

When drawing the skeleton structure of a molecule, which atom is typically placed in the center?

• The atom with the highest atomic mass

• The least electronegative atom

• The atom with the most valence electrons

• The most electronegative atom

In the context of Lewis structures, what does the octet rule refer to?

• Atoms tend to have eight neutrons

• Atoms tend to have eight protons in their nucleus

• Atoms tend to form eight bonds

• Atoms tend to have eight electrons in their outer shell

Which of the following elements is known for forming stable compounds with fewer than eight valence electrons?

• Carbon

• Nitrogen

• Oxygen

• Boron

Which of the following is a common exception to the octet rule?

• Sodium chloride (NaCl)

• Carbon dioxide (CO2)

• Boron trifluoride (BF3)

• Water (H2O)

Why can elements from period 3 onwards have more than eight valence electrons?

• They have extra orbitals available

• They are more electronegative

• They have a higher atomic mass

• They have more protons

What happens to aluminum chloride (AlCl3) when it is heated?

• It remains a solid

• It forms a liquid of Al2Cl6

• It decomposes into aluminum and chlorine

• It forms a gas of Al3 molecules

What is the total number of valence electrons in phosphorus pentafluoride (PF5)?

• 30

• 35

• 40

• 45

In the compound xenon tetrafluoride (XeF4), how many lone pairs are present around the xenon atom?

• One

• Two

• Three

• Four

Which molecule is an example of a compound that can have more than eight valence electrons?

• Sulfur hexafluoride (SF6)

• Ammonia (NH3)

• Water (H2O)

• Methane (CH4)