two friends are discussing physical and chemical changes. Isabela says that when you eat, it is a physical change because when you chew, the food is only changed into smaller pieces. Mirabel says that when you eat, it is a chemical change because your body digests the food as the chemicals in your body break down the food into energy. Who is right?(1 point)

Question

Responses

Mirabel
Mirabel

Isabela
Isabela

Both girls are correct
Both girls are correct

Neither girl is correct

Which event that takes place while baking cookies is an indicator of a physical change?

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(1 point)
Responses

All events are indicators of a chemical change
All events are indicators of a chemical change

Ingredients (flour, salt, sugar, milk, etc.) baking together in the oven
Ingredients (flour, salt, sugar, milk, etc.) baking together in the oven

Smell of cookies wafting from the oven
Smell of cookies wafting from the oven

Chocolate chips melting

Michael has recorded his observations while mixing vinegar and baking soda in a beaker.
observations before mixing observations after mixing
vinegar is a clear liquid the liquid remains clear
baking soda is a white solid many bubbles form
the remaining solid settles at the bottom
Which observation supports Michael’s claim that a chemical change has taken place?

(1 point)
Responses

The liquid remained clear after mixing the ingredients.
The liquid remained clear after mixing the ingredients.

Many bubbles formed after mixing the ingredients.
Many bubbles formed after mixing the ingredients.

The remaining solid settled after mixing the ingredients.
The remaining solid settled after mixing the ingredients.

All of the solid disappeared after mixing the ingredients.

Elizabeth was studying physical and chemical properties and created the table below to help her. Which property and example does she have correct?
type of property example
physical combustibility
chemical melting point
physical reactivity
chemical density
(1 point)
Responses

Melting point is a physical property. All other properties and examples in her table are correct.
Melting point is a physical property. All other properties and examples in her table are correct.

None of the properties and examples in her table are correct.
None of the properties and examples in her table are correct.

Melting point and density are both physical properties. All other properties and examples in her table are correct.
Melting point and density are both physical properties. All other properties and examples in her table are correct.

Density is a physical property. All other properties and examples in her table are correct.

Answer 1

1. Regarding the discussion between Isabela and Mirabel:

   • Mirabel is correct. Eating involves both physical and chemical changes. Chewing food is a physical change (breaking it into smaller pieces), but digestion is a chemical change because the body breaks down food into energy through chemical processes.

2. For the baking cookies question:

   • Smell of cookies wafting from the oven is an indicator of a physical change. This is because the smell doesn't involve a change in the composition of the ingredients; rather, it's the release of volatile molecules.

3. For Michael's observations with vinegar and baking soda:

   • Many bubbles formed after mixing the ingredients. This observation supports the claim that a chemical change has taken place because the bubbles are a sign of a gas being produced (carbon dioxide), indicating a reaction.

4. For Elizabeth's study on properties:

   • None of the properties and examples in her table are correct. Melting point and density are physical properties, while combustibility and reactivity are chemical properties.