Chemical Interactions

All of the following are properties of bases EXCEPT

• a. a bitter taste.

• b. react with metals.

• c. a slippery feeling.

• d. turn red litmus blue.

In the chemical equation CH₄ + 2O₂ → CO₂ + 2H₂O, how does the total mass of the reactants compare to the total mass of the products?

• a. The reactants have greater mass.

• b. The products have greater mass.

• c. You need more information.

• d. The total masses are the same.

To start and maintain a fire, you need all of the following EXCEPT

• a. carbon dioxide.

• b. oxygen.

• c. fuel.

• d. heat.

The BEST evidence for a chemical reaction is

• a. the formation of a new substance.

• b. the production of a gas.

• c. a change in color.

• d. the formation of a solid.

An atom has a neutral charge because

• a. the atom has twice as many neutrons as protons.

• b. the atom has the same number of protons and neutrons.

• c. the atom has the same number of protons and electrons.

• d. the atom has the same number of electrons and neutrons.

Elements in the same group of the periodic table share characteristics because they have the same

• a. number of protons.

• b. atomic mass.

• c. number of valence electrons.

• d. atomic number.

Which of the following compounds contains covalent bonds?

• a. NaCl

• b. CaF₂

• c. MgO

• d. H₂O

A tablespoon of salt is thoroughly mixed into a cup of water. The water acts as a

• a. solvent.

• b. solute.

• c. solution.

• d. suspension.

An acid is a substance that

• a. forms hydrogen ions in water.

• b. has a pH above 7.

• c. forms hydroxide ions in water.

• d. turns red litmus paper blue.

The main function of enzymes in chemical digestion is

• to build up proteins.

• to convert starches to amino acids.

• to lower the pH of the digestive system.

• to speed up reactions by acting as catalysts.