Question 1

A certain element contains eleven atoms of mass 95.952 u for every four atoms of mass 98.949 u.Compute the average atomic weight of this element.

Accepted Answer

A) 97.451 u 
B) 96.751 u 
C) 98.150 u 
D) 105.16 u 
E) 96.952 u 
A) 97.451 u 
B) 96.751 u 
C) 98.150 u 
D) 105.16 u 
E) 96.952 u

Question 2

An element has 5 stable isotopes.The mass and percentage of each are:
 
The element is which of the following?

Accepted Answer

A) Nb 
B) Y 
C) Sr 
D) Zr 
E) Rb 
A) Nb 
B) Y 
C) Sr 
D) Zr 
E) Rb

Question 3

Iodine belongs to the ________ group of the periodic table.

Accepted Answer

A) alkali metal 
B) alkaline earth metal 
C) halogen 
D) noble gas 
A) alkali metal 
B) alkaline earth metal 
C) halogen 
D) noble gas

Question 4

Which of the following elements is a gas at room temperature?

Accepted Answer

A) bromine 
B) carbon 
C) helium 
D) sodium 
A) bromine 
B) carbon 
C) helium 
D) sodium

Question 5

Iodine is a member of the family called ________.

Accepted Answer

A) metals 
B) metalloids 
C) noble gasses 
D) halogens 
E) actinides 
A) metals 
B) metalloids 
C) noble gasses 
D) halogens 
E) actinides

Question 6

A 25 g sample of sugar is found to contain 51.4% oxygen by mass.Another 250 g sample of the same sugar is also 51.4% oxygen by mass.This is consistent with the:

Accepted Answer

A) law of conservation of mass 
B) law of constant composition 
C) law of multiple proportions 
D) first assumption of Dalton's atomic theory 
E) second assumption of Dalton's theory 
A) law of conservation of mass 
B) law of constant composition 
C) law of multiple proportions 
D) first assumption of Dalton's atomic theory 
E) second assumption of Dalton's theory

Question 7

Argon belongs to the ________ group of the periodic table.

Accepted Answer

A) alkali metal 
B) alkaline earth metal 
C) halogen 
D) noble gas 
A) alkali metal 
B) alkaline earth metal 
C) halogen 
D) noble gas

Question 8

A cubic centimeter of lead weighs 11.35 g.How many atoms are in the block?

Accepted Answer

A) 6.8 × 1024  atoms 
B) 2.4 × 1023  atoms 
C) 3.3 × 1022  atoms 
D) 5.3 × 1022  atoms 
E) 1.1 × 1025  atoms 
A) 6.8 × 1024  atoms 
B) 2.4 × 1023  atoms 
C) 3.3 × 1022  atoms 
D) 5.3 × 1022  atoms 
E) 1.1 × 1025  atoms

Question 9

Copper occurs in an isotopic mixture of 69.09% 63Cu (mass = 62.93 u per atom)and 30.91% 65Cu (mass = 64.93 u per atom).What is the average atomic mass of copper?

Accepted Answer

A) 64.00 u 
B) 63.55 u 
C) 63.45 u 
D) 64.31 u 
E) 29.00 u 
A) 64.00 u 
B) 63.55 u 
C) 63.45 u 
D) 64.31 u 
E) 29.00 u

Question 10

Robert Millikan determined the charge on an electron.

Accepted Answer

A) True 
 B)False

Question 11

How many atoms of sulfur are in 280 g of a 50% by mass H2SO4 solution?

Accepted Answer

A) 8.6 × 1025 atoms 
B) 8.6 × 1023 atoms 
C) 8.0 × 1025 atoms 
D) 8.0 × 1023 atoms 
E) 2.8 × 1029 atoms 
A) 8.6 × 1025 atoms 
B) 8.6 × 1023 atoms 
C) 8.0 × 1025 atoms 
D) 8.0 × 1023 atoms 
E) 2.8 × 1029 atoms

Question 12

A sample of pure carbon weighing 1.48 g was burned in an excess of air.The mass of carbon dioxide,the sole product,was  
.In a second experiment,11.62 g of carbon dioxide was obtained.What mass of carbon was burned in the second experiment?

Accepted Answer

A) 42.6 g 
B) 3.17 g 
C) 3.54 g 
D) 0.866 g 
E) 11.6 g 
A) 42.6 g 
B) 3.17 g 
C) 3.54 g 
D) 0.866 g 
E) 11.6 g

Question 13

Choose the INCORRECT statement from those given below.

Accepted Answer

A) Atoms retain their identity during a chemical reaction. 
B) All matter is composed of atoms. 
C) Atoms combine in small,whole-numbered ratios. 
D) All atoms of a given element have same mass. 
E) Different ratios of atoms produce different compounds. 
A) Atoms retain their identity during a chemical reaction. 
B) All matter is composed of atoms. 
C) Atoms combine in small,whole-numbered ratios. 
D) All atoms of a given element have same mass. 
E) Different ratios of atoms produce different compounds.

Question 14

Atoms combine in small,whole-numbered ratios.

Accepted Answer

A) True 
 B)False

Question 15

A 3.214 g sample of magnesium reacts with 8.416 g of bromine.The only product is magnesium bromide.If 1.934 g of magnesium is left unreacted,how much magnesium bromide is formed?

Accepted Answer

A) 1.280 g 
B) 5.202 g 
C) 9.696 g 
D) 7.136 g 
E) 3.268 g 
A) 1.280 g 
B) 5.202 g 
C) 9.696 g 
D) 7.136 g 
E) 3.268 g

Question 16

Dalton's atomic theory is based on several assumptions,which are listed below.Which of these assumptions is strictly correct?
I.All atoms of the same element are identical.
II.Atoms are indivisible and unchangeable.
III.Chemical changes are the result of the combination,separation,and rearrangement of atoms.

Accepted Answer

A) I,II,and III are correct. 
B) I and III are correct. 
C) II and III are correct. 
D) I and II are correct. 
E) III is correct. 
A) I,II,and III are correct. 
B) I and III are correct. 
C) II and III are correct. 
D) I and II are correct. 
E) III is correct.

Question 17

Which statement below is true?

Accepted Answer

A) Metals gain electrons to have a positive charge. 
B) Metals gain electrons to have a negative charge. 
C) Metals lose electrons to have a positive charge. 
D) Nonmetals are more likely to lose than to gain electrons. 
E) Transition metals can gain 2 or more electrons to become metal ions. 
A) Metals gain electrons to have a positive charge. 
B) Metals gain electrons to have a negative charge. 
C) Metals lose electrons to have a positive charge. 
D) Nonmetals are more likely to lose than to gain electrons. 
E) Transition metals can gain 2 or more electrons to become metal ions.

Question 18

How many moles are represented by 2.5 × 1015 Na atoms?

Accepted Answer

A) 3.8 × 10-10 mol 
B) 1.8 × 10-10 mol 
C) 1.5 × 1039 mol 
D) 4.2 × 10-9 mol 
E) 1.1 × 1014 mol 
A) 3.8 × 10-10 mol 
B) 1.8 × 10-10 mol 
C) 1.5 × 1039 mol 
D) 4.2 × 10-9 mol 
E) 1.1 × 1014 mol

Question 19

Which of the following elements has chemical properties similar to tellurium?

Accepted Answer

A) fluorine 
B) hydrogen 
C) nitrogen 
D) sulfur 
A) fluorine 
B) hydrogen 
C) nitrogen 
D) sulfur

Question 20

The average atomic mass of B is 10.80 u.Boron has only two stable forms  
And  
What is the natural percent abundance of  B?

Accepted Answer

A) 80.0% 
B) 20% 
C) 1.0% 
D) 3.8% 
E) 75% 
A) 80.0% 
B) 20% 
C) 1.0% 
D) 3.8% 
E) 75%

Exam 2: Atoms and the Atomic Theory

A certain element contains eleven atoms of mass 95.952 u for every four atoms of mass 98.949 u.Compute the average atomic weight of this element.

An element has 5 stable isotopes.The mass and percentage of each are: The element is which of the following?

Iodine belongs to the ________ group of the periodic table.

Which of the following elements is a gas at room temperature?

Iodine is a member of the family called ________.

A 25 g sample of sugar is found to contain 51.4% oxygen by mass.Another 250 g sample of the same sugar is also 51.4% oxygen by mass.This is consistent with the:

Argon belongs to the ________ group of the periodic table.

A cubic centimeter of lead weighs 11.35 g.How many atoms are in the block?

Copper occurs in an isotopic mixture of 69.09% 63Cu (mass = 62.93 u per atom)and 30.91% 65Cu (mass = 64.93 u per atom).What is the average atomic mass of copper?

Robert Millikan determined the charge on an electron.

How many atoms of sulfur are in 280 g of a 50% by mass H2SO4 solution?

A sample of pure carbon weighing 1.48 g was burned in an excess of air.The mass of carbon dioxide,the sole product,was .In a second experiment,11.62 g of carbon dioxide was obtained.What mass of carbon was burned in the second experiment?

Choose the INCORRECT statement from those given below.

Atoms combine in small,whole-numbered ratios.

A 3.214 g sample of magnesium reacts with 8.416 g of bromine.The only product is magnesium bromide.If 1.934 g of magnesium is left unreacted,how much magnesium bromide is formed?

Which statement below is true?

How many moles are represented by 2.5 × 1015 Na atoms?

Which of the following elements has chemical properties similar to tellurium?

The average atomic mass of B is 10.80 u.Boron has only two stable forms And What is the natural percent abundance of B?

Matter: Its Properties and Measurement

Chemical Compounds

Chemical Reactions

Introduction to Reactions in Aqueous Solutions

Gases

Thermochemistry

Electrons in Atoms

The Periodic Table and Some Atomic Properties

Chemical Bonding I: Basic Concepts

Chemical Bonding Ii: Valence Bond and Molecular Orbital Theories

Intermolecular Forces: Liquids and Solids

Spontaneous Change: Entropy and Gibbs Energy

Solutions and Their Physical Properties

Principles of Chemical Equilibrium

Acids and Bases

Additional Aspects of Acidbase Equilibria

Solubility and Complex-Ion Equilibria

Electrochemistry

Chemical Kinetics

Chemistry of the Main-Group Elements I: Groups 1,2,13,and 14

Chemistry of the Main-Group Elements Ii: Groups 18,17,16,15,and Hydrogen

The Transition Elements

Complex Ions and Coordination Compounds

Nuclear Chemistry

Structures of Organic Compounds

Reactions of Organic Compounds

Chemistry of the Living State

Filters

Copper occurs in an isotopic mixture of 69.09% ⁶³Cu (mass = 62.93 u per atom)and 30.91% ⁶⁵Cu (mass = 64.93 u per atom).What is the average atomic mass of copper?

How many atoms of sulfur are in 280 g of a 50% by mass H₂SO₄ solution?

How many moles are represented by 2.5 × 10¹⁵ Na atoms?

The average atomic mass of B is 10.80 u.Boron has only two stable forms And What is the natural percent abundance of _B?