Chemical Reacations and Conservation of Matter

Multiple Choice

What is another term used to describe chemical changes?

• Physical reactions

• Chemical reactions

• Physical changes

• Energy changes

Multiple Choice

Which of the following best describes the difference between reactants and products in a chemical reaction?

• Reactants are created in the reaction, products take part in the reaction

• Reactants are substances that take part in the reaction, products are created in the reaction

• Reactants and products are the same

• Reactants are always gases, products are always solids

• Both sides of the chemical reaction are called chemical equations.

Multiple Choice

Based on the chemical equation Na + Cl → NaCl, identify the reactants and the product.

• Reactants: NaCl; Product: Na and Cl

• Reactants: Na and Cl; Product: NaCl

• Reactants: Na; Product: Cl and NaCl

• Reactants: Cl; Product: Na and NaCl

Multiple Choice

Which statement best describes the Law of Conservation of Matter as shown in the slides?

• Matter can be created and destroyed during a chemical reaction.

• Mass cannot be created or destroyed, and whatever is on one side of a chemical reaction must be on the other.

• Atoms change their identity during a chemical reaction.

• Energy is always conserved in every chemical reaction.

Multiple Select

Which of the following are true about the atoms in the reactants and products in the magnesium and oxygen reaction?

• The number of magnesium atoms is the same on both sides.

• The number of oxygen atoms is the same on both sides.

• The type of atoms changes during the reaction.

• The total number of atoms is conserved.

Multiple Choice

Which part of a chemical equation tells you the quantity of each element or formula present?

• Coefficient

• Subscript

• Arrow

• Chemical Symbol

Multiple Select

Select all the correct statements about the reactants and products in the equation Na + Cl₂ → NaCl.

• Na and Cl₂ are reactants.

• NaCl is the product.

• Cl₂ is a product.

• Na is a product.

Open Ended

Summarize the main differences between chemical and physical changes, and explain how you can identify if a chemical change has occurred.