Chemical Reactions Unit Review

What is an example of a chemical property?

• Flammability

• Toxicity

• Luster

• Malleability

Which of the following is evidence of a chemical reaction?

• fizzing
• water changing to ice
• saltwater
• paper being cut in half

What are Chemical Reactions?

• It's when you mix substances.
• a process in which atoms rearrange to form new substances
• When something bubbles.
• letter and numbers showing the types and number of atoms

A teacher is demonstrating physical and chemical changes to her class. Which action should she use to demonstrate a chemical change?

• cutting a piece of paper
• folding a piece of paper
• tearing a piece of paper
• burning a piece of paper

A granular substance is added to a liquid. Which of the following would provide evidence to suggest a chemical change has taken place?

• The liquid gives off heat.
• The granules dissolve completely.
• The volume of the liquid increases.
• The granules seem to get smaller.

How many Hydrogen are in 4H₂O + 2CH₄?

(a)  

Number of N in (NH₄)₂CrO₄

• 1
• 2
• 8
• 16

What is a coefficient?

• The small number on the right of the chemical symbol.
• The large number to the left of a formula.

The subscripts usually represents what?

• How many of that specific element is included in the equation

• How many elements of that whole equation is included

• How many protons total

• how many electrons total

The Coefficients are located where on the equation?

• At the very front of the equation

• Under the specific element in a smaller font

• It is invisible

• Underneath the whole equation to be divided