Mateo observes a white crystal that is cube-shaped under a microscope.

Question

Slightly white, almost clear cubes on a black background.

Based on this observation, Mateo thinks the crystal could be sodium chloride (table salt). Because the crystal has an extended structure, he knows that sodium chloride is not a molecule. Mateo uses gray and black spheres, representing the atoms in sodium chloride (NaCl), to make a model of the crystal's most likely structure, as shown.

A set of interconnecting cubes. The cubes share sides and corners. At each corner is a small black ball or a large gray ball. The colors alternate between the corners.

Select all of the reasons why the model accurately represents sodium chloride.

(2 points)
Responses

The model can be extended to show larger amounts of sodium chloride.
The model can be extended to show larger amounts of sodium chloride.

Mateo used gray to represent the sodium atoms and black to represent the oxygen atoms.
Mateo used gray to represent the sodium atoms and black to represent the oxygen atoms.

Mateo's model shows a repeating pattern of sodium and chlorine atoms.
Mateo's model shows a repeating pattern of sodium and chlorine atoms.

Sodium chloride is composed of four kinds of atoms.
Sodium chloride is composed of four kinds of atoms.
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Answer 1

The accurate reasons why Mateo's model represents sodium chloride are:

1. The model can be extended to show larger amounts of sodium chloride.
2. Mateo's model shows a repeating pattern of sodium and chlorine atoms.

The other statements are inaccurate. Specifically:

• Mateo used gray to represent the sodium atoms and black to represent the oxygen atoms. This is incorrect; in sodium chloride (NaCl), Mateo should represent sodium (Na) with gray and chlorine (not oxygen) with black.

• Sodium chloride is composed of four kinds of atoms. This is also incorrect; sodium chloride is composed of two types of atoms: sodium (Na) and chlorine (Cl).