Question

NEED ANSWER FAST
1.Two chemist are trying to determine if their water sample is a mixture or pure substance. In their investigation they first filter the sample of dirty water with gravel. The water is then clearer then before. See image. What does this change tell the chemist about the chemical make up of the sample?
The dirty water is only a mixture because it was not completely filtered by the gravel.


A.Dirty water is a mixture of solid particles and liquid. It is both a mixture and pure substance.


B.More information is needed to answer the question.


C.The dirty water is only a pure substance now that it has been filtered by the gravel.


D.Dirty water is a mixture of solid particles and liquid. It is both a mixture and pure substance.

2.Candace has two diagrams of particles of substance A and substance B as shown below. She is classifying them as either pure substances or mixtures. In her conclusion, she stated, "Both substances are mixtures, because they are made up of different types of elements." Is Candace correct? Why or why not
Candace is correct. Both substances are mixtures, because they both contain different types of molecules.

A.Candace is correct. Both substances are mixtures, because they both contain different types of molecules.

B.Candace is incorrect. Substance B is a pure substance, because it is made up of molecules of only one type of element. Substance A is a mixture, because each molecule has different elements.


C.Candace is correct. Both substances are mixtures. Mixtures are any substances made up of two or more different types of elements.


D.Candace is incorrect. Substance A is a pure substances, because it is a compound. A compound is made up of two or more different elements. A mixture is made up of different molecules not bonded together.

3.Scientists Pam and Alejandro were discussing a liquid found in the science lab that was missing it's label. In classifying the unknown liquid, they first needed to determine if the liquid is a mixture or pure substance. How is a pure substance different from a mixture?
Mixtures cannot be separated by physical means.

A.Mixtures cannot be separated by physical mean

B. a pure substance is heterogeneous.


C.Pure substances cannot be separated by physical means.


D. a mixture is made of one substance.

Answer 1

Mixture: the components of a mixture can be separated by physical methods like filtration, decantation or magnetic separation etc

Compounds : the components cannot be separated by physical methods

1) the dirty water : we are able to separate the solid from the dirty water however water remains as such so

Dirty water is a mixture of solid particles and liquid. It is both a mixture and pure substance.

2) compound is pure substance made up of two more more types of elements

so the correct answer will be

D.Candace is incorrect. Substance A is a pure substances, because it is a compound. A compound is made up of two or more different elements. A mixture is made up of different molecules not bonded together.

3) Mixture can be separated by physical methods

pure substances cannot be separated by physical means

mixture is made up of two or more substance

a pure substance is homogeneous