7.3 Quiz Review Lesson 10-14

What happens to the mass in an OPEN system when food burns?

• The mass would decrease

• The mass would stay exactly the same

• The mass would increase

• the mass would multiply

In a CLOSED system, why does the mass remain unchanged after burning?

• The mass evaporates

• The mass becomes zero

• The mass is absorbed into the wick

• The mass of gases is contained and measured

Why is burning considered a CHEMICAL reaction?

• New substances are formed

• The food changes color

• The food melts

• The food becomes hotter

Where do the atoms that make up Carbon Dioxide and Water molecules come from during the burning of food?

• They come from the food being burned

• They appear from nowhere

• They are created inside the flame

• They come from the air around the flame

What evidence best supports that a chemical reaction is happening in our bodies?

• The air we breathe is a mixture of several gasses

• We inhale oxygen and exhale carbon dioxide

• We feel sleepy after eating

• Our body temperature remains constant

What are the main REACTANTS in the burning of food?

• Water & Air

• Sunlight & Heat

• Oxygen & the food molecules

• Carbon Dioxide & Hydrogen

What is formed when food molecules burn completely?

• Carbon Dioxide & Water

• Hydrogen & Oxygen

• Methane & Nitrogen

• Solid Residue & Ash

Why might burning food release energy?

• Because it releases light

• Because the food is hot

• Because the bonds in the molecules are breaking

• Because it changes color

What is the relationship between burning a tree branch & cellular respiration in our bodies?

• Both need Carbon Dioxide to start

• Both make us feel hot

• Both require large flames

• Both release energy through chemical reactions

What can you infer from the fact that gases like CO2 can be detected after burning fat?

• New atoms are created

• Atoms in the fat are rearranged

• Air creates gases

• The fat evaporates