8th Grade Science Blitz Day 2

Students investigate physical and chemical changes in matter. Their observations are recorded in the table. Identify the type of change in each observation.

Groups:

(a) Physical Change

,

(b) Chemical Change

• A liquid was poured into a flask, and the liquid took the shape of the container.

• Two substances were mixed in a petri dish, and bubbles formed.

• A liquid in one test tube was mixed with a liquid in another test tube, and a solid substance fo

• A beaker of water was heated on a hot plate, and steam formed.

How does the balanced equation support the law of conservation of mass?

Which statements provide the best evidence that mass is conserved in the reaction?

Select TWO correct answers.

• Four hydrogen atoms are in the reactants, and four hydrogen atoms are in the products.

• The atoms in the reactants are different than the atoms in the products.

• Five oxygen atoms are in the reactants, and ten oxygen atoms are in the products.

• The atoms in the reactants are the same as the atoms in the products.

• The compounds in the reactants are different than the compounds in the products.

Which of the following observations indicate evidence of a chemical change?

Select THREE correct answers.

• 
• 
• 
• 
• 

How does the balanced equation support the law of conservation of mass?

Does digesting food in the stomach represent a physical change or chemical change? Explain.

Ethanol is burned as fuel, which releases carbon dioxide into the atmosphere. The chemical equation for the combustion of ethanol is shown.

What types of atoms are represented in this equation?

Ethanol is burned as fuel, which releases carbon dioxide into the atmosphere. The chemical equation for the combustion of ethanol is shown.

How many atoms of each element are represented in the reactants of this equation?

Ethanol is burned as fuel, which releases carbon dioxide into the atmosphere. The chemical equation for the combustion of ethanol is shown.

How many atoms of each element are represented in the products of this equation?

Ethanol is burned as fuel, which releases carbon dioxide into the atmosphere. The chemical equation for the combustion of ethanol is shown.

How many compounds are represented in the reactants of this equation?

Ethanol is burned as fuel, which releases carbon dioxide into the atmosphere. The chemical equation for the combustion of ethanol is shown.

What is the total mass of the products in this reaction? Explain.