Review for Test 1

Chalk is a combination of calcium, carbon, and oxygen atoms, CaCO3​. Chalk is  —

• a compound

• an element

• a solution

• a mixture

Mary's mother has a perfect diamond she wants to put into a necklace setting. Diamonds are made of compressed carbon. Select the symbol and atomic number for diamonds.

• C-16

• Ca-6

• C-6

• Di-20

An atom of a certain element has a mass of 14. This atom is —

• silicon, which has 7 protons and 7 neutrons.

• nitrogen, which has 7 protons and 7 neutrons.

• silicon, which has 14 protons and 14 neutrons.

• nitrogen, which has 14 protons and 14 neutrons.

The diagram shows a chemical reaction.


Which of the following most likely describes the reaction in the diagram?

• The heat created a chemical reaction between the iron and sulfur, creating a compound of iron sulfide with new chemical properties.

  
  

• The heat created a physical reaction between the iron and sulfur, creating a mixture with new physical properties.

  
  

• The heat evaporated the iron and sulfur, creating a precipitate with new chemical properties.

  
  

• The heat melted the iron and sulfur, creating a solution with new physical properties.

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Unknown elements W and X interacted to form a new substance. This indicates that W and X must have experienced a —

• temperature change.

• chemical change.

• physical change.

• phase change.

Which of the following is NOT a compound?

• FeO

• CO

• H₂O₂

• Fe

Iron is a metal element used for a wide variety of objects, including cast-iron frying pans. Select the symbol and atomic number for iron.

• I-20

• Fe-25

• I-77

• Fe-26

• I-9

Which substance cannot be decomposed by a chemical change?

• HF

• H20

• Ne

• N20

• C02

In an experiment the teacher put water in a glass bowl and began to heat it. The water began to bubble after a few minutes. What change is occurring?

• Physical Change

• Chemical Change

• New Substance