Question 1

Water and hydrogen peroxide are compounds composed of only hydrogen and oxygen.These compounds illustrate the Law of Multiple Proportions.

Accepted Answer

A) True 
 B)False

Question 2

Sample A contains 92.3%carbon and 7.7% hydrogen.If sample B is the same substance,it will contain

Accepted Answer

A) 80% carbon and 20% hydrogen. 
B) 92.3% carbon and 7.7% hydrogen. 
C) 83.3% carbon and 16.7% hydrogen. 
D) 85% carbon and 15% hydrogen. 
A) 80% carbon and 20% hydrogen. 
B) 92.3% carbon and 7.7% hydrogen. 
C) 83.3% carbon and 16.7% hydrogen. 
D) 85% carbon and 15% hydrogen.

Question 3

The ancient Greeks believed that matter was composed of four basic elements.Which one of the following was NOT one of the four?

Accepted Answer

A) mercury 
B) air 
C) water 
D) earth 
A) mercury 
B) air 
C) water 
D) earth

Question 4

A student measures 10.5 g of mercury(II)oxide into an open test tube and heats the tube.The heat causes the mercury(II)oxide to decompose into mercury and oxygen.After reaction,the student finds the mass of the contents of the tube to be 9.7 g.Which one of the following describes these observations?

Accepted Answer

A) The decomposition of mercury(II)oxide does not obey the Law of Conservation of Mass. 
B) 0)8 grams of oxygen gas are lost from the tube. 
C) There are errors associated with the student's measurements. 
D) Heating destroys some mass. 
A) The decomposition of mercury(II)oxide does not obey the Law of Conservation of Mass. 
B) 0)8 grams of oxygen gas are lost from the tube. 
C) There are errors associated with the student's measurements. 
D) Heating destroys some mass.

Question 5

Which of the following parts (postulates)of Dalton's atomic theory has been modified in light of later discoveries?

Accepted Answer

A) All matter is made up of very small particles called atoms. 
B) Atoms are indivisible. 
C) Chemical reactions involve rearrangement of atoms. 
D) Compounds are formed from atoms. 
A) All matter is made up of very small particles called atoms. 
B) Atoms are indivisible. 
C) Chemical reactions involve rearrangement of atoms. 
D) Compounds are formed from atoms.

Question 6

________ was the first person to propose a consistent "modern" atomic theory.

Accepted Answer

A) Dalton 
B) Democritus 
C) Proust 
D) Lavoisier 
A) Dalton 
B) Democritus 
C) Proust 
D) Lavoisier

Question 7

Lavoisier's experiments showed that matter can be gained or lost in a chemical change.

Accepted Answer

A) True 
 B)False

Question 8

How many years ago was an atomic view of matter was first proposed?

Accepted Answer

A) 50 
B) 100 
C) 200 
D) 2500 
A) 50 
B) 100 
C) 200 
D) 2500

Question 9

Which of the following postulates of Dalton's atomic theory has been modified in light of later discoveries?

Accepted Answer

A) All matter is made up of very small particles called atoms. 
B) All atoms of an element are identical. 
C) Chemical reactions involve rearrangement of atoms. 
D) Compounds are formed from atoms. 
A) All matter is made up of very small particles called atoms. 
B) All atoms of an element are identical. 
C) Chemical reactions involve rearrangement of atoms. 
D) Compounds are formed from atoms.

Question 10

One mole is of carbon is equal to

Accepted Answer

A) 6)022 × 10²³ atoms of carbons. 
B) 12.011 grams of carbon. 
C) Avogadro's number of atoms. 
D) all of the above. 
A) 6)022 × 10²³ atoms of carbons. 
B) 12.011 grams of carbon. 
C) Avogadro's number of atoms. 
D) all of the above.

Question 11

In light of present day knowledge,comment on Dalton's proposal that atoms are indivisible.

Accepted Answer

Radioactive elements decompose

Question 12

After many observations,Proust stated that elements combine in definite proportions to form compounds.Dalton explained these observations by proposing that matter must consist of atoms.Dalton's explanation is called a(n)

Accepted Answer

A) law. 
B) theory. 
C) hypothesis. 
D) observation. 
A) law. 
B) theory. 
C) hypothesis. 
D) observation.

Question 13

Which of the following is an example of green chemistry?

Accepted Answer

A) building new coal-fired plants to generate electricity 
B) developing new technologies that require rare elements 
C) using materials that are made up of substances that are very abundant in the earth's crust 
D) using lead as a plasticizer to make plastics less rigid 
A) building new coal-fired plants to generate electricity 
B) developing new technologies that require rare elements 
C) using materials that are made up of substances that are very abundant in the earth's crust 
D) using lead as a plasticizer to make plastics less rigid

Question 14

The scientist who in 1828 published a table of atomic weights containing 54 elements was

Accepted Answer

A) Dalton. 
B) Berzelius. 
C) Mendeleev. 
D) Boyle. 
A) Dalton. 
B) Berzelius. 
C) Mendeleev. 
D) Boyle.

Question 15

No matter how much extra oxygen is available,12 grams of carbon always combines with 32 grams of oxygen.This best illustrates the Law of

Accepted Answer

A) Conservation of Mass. 
B) Definite Proportions. 
C) Multiple Proportions. 
D) Conservation of Energy. 
A) Conservation of Mass. 
B) Definite Proportions. 
C) Multiple Proportions. 
D) Conservation of Energy.

Question 16

All of the following are molecules EXCEPT ________.

Accepted Answer

A) H₂ 
B) NO 
C) H 
D) O₃ 
A) H₂ 
B) NO 
C) H 
D) O₃

Question 17

The "box" for an element on the periodic table will include all of the following information about an element EXCEPT

Accepted Answer

A) its atomic number. 
B) the proportion of the element in a compound. 
C) its atomic symbol. 
D) its atomic mass. 
A) its atomic number. 
B) the proportion of the element in a compound. 
C) its atomic symbol. 
D) its atomic mass.

Question 18

Approximately how many elements occur naturally on Earth?

Accepted Answer

A) 20 
B) 60 
C) 90 
D) 115 
A) 20 
B) 60 
C) 90 
D) 115

Question 19

Which one of the following does NOT occur in a chemical reaction?

Accepted Answer

A) Matter is rearranged. 
B) Matter is conserved. 
C) Atoms react with other atoms. 
D) Atoms are changed into other atoms. 
A) Matter is rearranged. 
B) Matter is conserved. 
C) Atoms react with other atoms. 
D) Atoms are changed into other atoms.

Question 20

During a chemical reaction,matter can neither be created nor destroyed.

Accepted Answer

A) True 
 B)False

Exam 2: Atoms

Water and hydrogen peroxide are compounds composed of only hydrogen and oxygen.These compounds illustrate the Law of Multiple Proportions.

Sample A contains 92.3%carbon and 7.7% hydrogen.If sample B is the same substance,it will contain

The ancient Greeks believed that matter was composed of four basic elements.Which one of the following was NOT one of the four?

Which of the following parts (postulates)of Dalton's atomic theory has been modified in light of later discoveries?

________ was the first person to propose a consistent "modern" atomic theory.

Lavoisier's experiments showed that matter can be gained or lost in a chemical change.

How many years ago was an atomic view of matter was first proposed?

Which of the following postulates of Dalton's atomic theory has been modified in light of later discoveries?

One mole is of carbon is equal to

In light of present day knowledge,comment on Dalton's proposal that atoms are indivisible.

After many observations,Proust stated that elements combine in definite proportions to form compounds.Dalton explained these observations by proposing that matter must consist of atoms.Dalton's explanation is called a(n)

Which of the following is an example of green chemistry?

The scientist who in 1828 published a table of atomic weights containing 54 elements was

No matter how much extra oxygen is available,12 grams of carbon always combines with 32 grams of oxygen.This best illustrates the Law of

All of the following are molecules EXCEPT ________.

The "box" for an element on the periodic table will include all of the following information about an element EXCEPT

Approximately how many elements occur naturally on Earth?

Which one of the following does NOT occur in a chemical reaction?

During a chemical reaction,matter can neither be created nor destroyed.

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