chemistry unit test forrest mod ap 23-24.

Which of the following is the best example of a chemical change?

• Cutting hair

• Melting butter

• Shredding cheese

• Souring milk

Which of the following is the best example of a physical change?

• Toasting bread

• Melting wax

• Frying an egg

• Rusting metal

A student mixes two chemicals in a test tube. She notices that the mixture starts to bubble and the test tube feels very warm. The student most likely concludes that this mixture is –

• A chemical reaction did not happen.

• An endothermic reaction that absorbed thermal energy.

• An exothermic reaction that released thermal energy.

• It’s a physical reaction because it’s only a mixture

Which of the following subatomic particles are found in the nucleus and have a neutral charge?

• Neutrons

• Protons

• Negatrons

• Electrons

Which of the following subatomic particles are found in the nucleus and have a positive charge?

• Positrons

• Neutrons

• Protons

• Electrons

Which group on the periodic table of elements is considered the noble gases?

• 8A

• 6A

• 5A

• 2A

What type of chemical reaction releases heat into the surrounding environment?

• Endothermic

• Homothermic

• Heterothermic

• Exothermic

What is described by the phrase: "a positive nucleus surrounded by a cloud of negative charges"?

• An atom

• A compound

• A proton

• An electron

Elements on the periodic table are arranged according to their

• Atomic mass

• Number of neutrons

• Color, shape and size

• Atomic number

Which of the following is the element in group 6A and Period 2 on the periodic table?

• Sulfur

• Nitrogen

• Oxygen

• Fluorine