S.4 Structure of Matter Final Exam

Which of the following is true about how oxygen and hydrogen can combine to form molecules?

• Hydrogen and oxygen can combine in many ways to form different molecules.

• Two atoms of hydrogen are always required to bond with two atoms of oxygen.

• When hydrogen combines with oxygen to make a molecule, the result will always be water.

• Molecules composed of hydrogen and oxygen must have at least 4 atoms.

Which of the following best explains the relationship between molecules and atoms?

• Atoms are molecules that have a charge.

• Atoms have smaller parts called molecules.

• Molecules are made up of 2 or more atoms.

• Molecules are atoms that have no mass.

The extended structure of Sodium Chloride (NaCl) is shown to the left.

Which of the following describes the configuration of Layer 4 of the sodium chloride crystal?

• It will be identical in all its characteristics to Layer 1.

• It will contain 4 atoms of Chlorine and 5 atoms of Sodium.

• It will have Chlorine atoms in all four of its corners.

• It will have sodium that are bonded only to other sodium atoms.

Students are asked to create models of molecules using marbles of different colors to represent atoms of different types. To the left is a table describing the models made by four students.

Which of the following the most accurate evaluation of these models?

• Only students 1, 2, and 4 created acceptable models, since molecules must be made of different types of atoms.

• All of the students created acceptable models because molecules can consist of many different configurations of atoms.

• Only student 2 created an acceptable model of molecules, since every molecules must have a balance of atoms.

• All student models are acceptable except that of student 4, since molecules can't be made of so high a number of atoms.

Atomic models of graphite and diamond are shown.

Graphite is a soft, dark material often used as a lubricant. Diamond is often a clear, hard crystal.

Which of the following best explains the difference in these materials?

• The arrangement of the atoms of each one.

• The elements of which each one is made.

• The number of atoms each one is made of.

• The size and shape of the individual atoms.

How many atoms are needed to form a molecule?

The model to the left was used to show a molecule of Methane, or CH₄.

Describe the number and type of each component of the molecule.

Methane (CH₄) combines with oxygen gas (O₂) to form carbon dioxide (CO₂) and water (H₂O). Describe the number and type of atoms for a molecule of each substance.

Scenario

Three compounds have been discovered that are completely made out of carbon: graphite, diamond, and a newly discovered molecule called buckminsterfullerene. They are allotropes of carbon and have very different properties.

Evidence

Your evidence is the image to the left. Click on it to review the information.

Prompt

Write a scientific explanation in the form of a CER about how diamonds and graphite can both be made of pure carbon yet still be so different.