chemical reaction

2. A scientist mixed two samples together: a colorless liquid that melts at 12°C and a yellow solid that melts at 390°C. She analyzed the results and found two ending substances. One of the ending substances was a gray solid. This ending substance is made up of the repeating group of atoms shown above. Which of the diagrams to the left shows the repeating groups of atoms that make up the samples the scientist mixed together?

• 
• Diagram A

• Diagram B

• Diagram C and D

3. A  company that makes frying pans needs to create a new substance to coat the pans. The substance must have a high melting point. To create this new substance, workers mixed together two substances that melt at low temperatures in a sealed container. The diagram above shows the repeating groups of atoms that make up the two starting substances.

After mixing, the workers found two substances that melt at higher temperatures in the sealed container. (Nothing had escaped.) Which of the diagrams to the left shows the repeating groups of atoms that make up the ending substances?

• 
• Diagram A and B

• Diagram C and D

• Diagram A

4. The diagram above shows the repeating groups of atoms that make up two samples. Both samples are gases at room temperature. Will the other properties of the samples likely be the same or different? (Examples of properties are smell, color, and the temperature at which a substance melts.)

• The other properties will likely be the same because the repeating groups of atoms that make up the two samples have the same types of atoms.

• The other properties will likely be the same because both samples are gases at room temperature.

• The other properties will likely be different because there are more repeating groups of atoms in Sample 1.

• The other properties will likely be different because the repeating groups of atoms that make up the two samples have different numbers of atoms.

5. A scientist mixed two samples together: a white solid that boils at about 800°C and a colorless gas that boils at about 70°C. He analyzed the results and found two ending substances. One of the ending substances boils at 245°C. This ending substance is made up of the repeating group of atoms shown above. Which of the diagrams to the left shows the repeating groups of atoms that make up the samples the scientist mixed together?

• 
• Diagram A

• Diagram B and D

• Diagram C

• 
• Diagram A

• Diagram B

• Diagram C and D

7. The diagram above shows the repeating groups of atoms that make up two samples. Both samples are solids at room temperature. Will the other properties of the two samples likely be the same or different? (Examples of properties are smell, color, and the temperature at which a substance melts.)

• The other properties will likely be different because there are more repeating groups of atoms in Sample 2.

• The other properties will likely be different because the repeating groups of atoms that make up the two samples have different numbers of atoms. 

• The other properties will likely be the same because the repeating groups of atoms that make up the two samples have the same types of atoms.

• The other properties will likely be the same because both samples are solids at room temperature.

The other properties will likely be the same because both samples are solids at room temperature.

• 
• Diagram D

• Diagram A

• Diagram B

9. Paula works at a paint company and is developing new ingredients to make paint safer to use. She mixed two colorless substances together in a sealed container. The diagram above shows the repeating groups of atoms that make up the two starting substances.

After mixing, Paula found two yellow substances in the sealed container. (Nothing had escaped.) Which of the diagrams to the left shows the repeating groups of atoms that make up the ending substances?

• 
• Diagram B

• Diagram C

• Diagram D

10. The diagram above shows the repeating groups of atoms that make up two samples. Both samples are red powdery solids at room temperature. Will the other properties of the two samples be the same or different? (Examples of properties are smell, color, and the temperature at which a substance melts.)

• The other properties will be different because there are more repeating groups of atoms in Sample 1.

• The other properties will be the same because both samples are red at room temperature.

• The other properties will be the same because both samples are powdery solids at room temperature.

• The other properties will be same because the repeating groups of atoms that make up the two samples are the same.

11. A chemist mixed two samples together: a brown solid that melts at about 1,300°C and a colorless liquid that melts at about 20°C. She analyzed the results and found two ending substances. One of the ending substances melts at about 250°C. This ending substance is made up of the repeating group of atoms shown above. Which of the diagrams to the left shows the repeating groups of atoms that make up the samples the chemist mixed together?

• 
• Diagram A

• Diagram C and D

• Diagram D