review lab chocolate chip cookies

Two or more elements chemically combined, whose properties are completely different from those of the individual elements, are known as ____.

• Compound

• Heterogeneous

• Homogeneous

• Solution

Answer explanation

A compound is formed when two or more elements chemically combine, resulting in new properties that differ from those of the individual elements. Therefore, the correct answer is 'Compound'.

Tags

NGSS.MS-PS1-5

After the butter and sugars are creamed, what type of mixture is it?

• heterogeneous

• homogeneous

Answer explanation

After creaming butter and sugars, the mixture becomes homogeneous because the ingredients blend uniformly, creating a consistent texture and appearance without visible separation.

After the chocolate chips are added, what type of mixture is it?

• heterogeneous

• homogeneous

Answer explanation

After adding chocolate chips, the mixture is heterogeneous because the chips remain distinct and can be seen separately from the dough, unlike a homogeneous mixture where components are uniformly distributed.

Pure substances ____.

• Are made of up of only one material

• Have definite and constant properties under certain conditions

• Are elements or compounds

• All of these are correct

• None of the above

Answer explanation

Pure substances are defined as materials made of only one type of particle, exhibiting consistent properties under specific conditions, and can be classified as elements or compounds. Therefore, all statements are correct.

Tags

NGSS.MS-PS1-4

Which of the following involves a chemical change?

• Combining baking soda and vinegar

• Combining salt and water

• Sweetening iced tea

• Tossing salad

Answer explanation

Combining baking soda and vinegar results in a chemical reaction that produces carbon dioxide gas, indicating a chemical change. The other options involve physical changes, not chemical reactions.

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

What is an example of a reversible physical change?

• Change in color

• Chopping

• State change

• Rusting

Answer explanation

A state change, such as melting or freezing, is reversible because the substance can return to its original state. In contrast, rusting and chopping are irreversible changes, while a change in color may not indicate a physical change.

Tags

NGSS.MS-PS1-4

An example of an element is___. (in modern chemistry)

• Air

• Iron

• Water

• Fire

Answer explanation

An element is a pure substance that cannot be broken down into simpler substances. Iron is a chemical element, while air, water, and fire are not elements; they are mixtures or compounds.

Tags

NGSS.MS-PS1-1

An example of heterogeneous mixture is ____.

• Cola (flat)

• Tea

• Sodium Chloride

• Tossed Salad

Answer explanation

A tossed salad is a heterogeneous mixture because it contains different components (lettuce, tomatoes, etc.) that remain distinct and can be easily separated. In contrast, cola and tea are homogeneous mixtures.

Which of the following involves a chemical change?

• roasting vegetables

• Combining salt and water

• Sweetening iced tea

• Tossing salad

Answer explanation

Combining baking soda and vinegar results in a chemical reaction that produces carbon dioxide gas, indicating a chemical change. The other options involve physical changes, not chemical reactions.

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

An example of a compound is ____.

• Salt

• Salt water

• Sodium

• Soft drinks

Answer explanation

Salt is a compound formed from the chemical combination of sodium and chlorine. Unlike salt water, which is a mixture, salt itself is a pure substance, making it the correct example of a compound.

Tags

NGSS.MS-PS1-1