8th Grade Comp 2

Which of the following solids uses a "sea" of electrons to hold its shape?

• Mn (s)

• H₂O (s)

• NaCl (s)

• H₂ (s)

Which statement best describes metallic bonding?

• It is the electrostatic interaction between the positive metal ions and delocalized electrons.

• It is the electrostatic interaction between the electrons and delocalized protons.

• It is delocalized electrons.

• It is delocalized protons.

Which of the following statements is FALSE when describing the properties of a metal due to its “sea of electrons” bonding model?

• Metals are great conductors because their electrons are free to flow throughout the material.

• Metals are malleable because bonds can be easily broken and reformed.

• Metals have a low boiling point because metal atoms are weakly bonded to one another and have weak attractive forces.

• Metals are shiny because light cannot penetrate the surface of the metal and are therefore reflected off the surface.

What is the molar mass of barium bromide?

• 1.72 g/mol

• 297.1 g/mol

• 217.2 g/mol

• 354.6 g/mol

You set up an experiment to react 1.00 g lead (Pb) and 1.00 g sulfur (S). Which of the two samples contains more atoms?

• There are more atoms of S than Pb.

• There are more atoms of Pb than S.

• There are equal numbers of atoms in both samples.

• Can’t determine because moles of each compound are not provided.

How many molecules are present in 22 moles of CO₂?

• 44 molecules

• 6.35 x 10²³ molecules

• 968 molecules

• 1.32 x 10²⁵ molecules

I have 2.3 mols of lithium chloride. How many grams of lithium chloride do I have?

• 2.3 grams

• 97.5 grams

• 42.39 grams

• 0.05 grams

How many particles of copper are in 0.912 moles of copper?

• 5.49 x 10^23 atoms of copper

• 348.9 x 10^25 particles copper

• 1.51 x 10^-24 particles

• 8.63 x 10^21 particles of copper

How many molecules are in 7.29 g of sugar, if the molar mass of table sugar is 342.49 g/mol?

• 2.49 x 10^3 molecules

• 1.28 x 10^22 molecules

• 2.13 x 10^-2 molecules

• 3.53 x 10^-26 molecules

What is the percent mass of oxygen in Mg(NO3)2 (MM = 148.3 g/mol) to the nearest hundreds place?

• 16.40%

• 18.89%

• 64.73%

• 66.66%