Question 1

In naturally occurring samples,all elements exist as a mixture of isotopes.

Accepted Answer

A) True 
 B)False  False

Question 2

The atomic mass number is a whole number and indicates a specific isotope of an element.

Accepted Answer

A) True 
 B)False  True

Question 3

How many electrons are found around the species below?

Accepted Answer

A)  -2 
B)  0 
C)  2 
D)  4 
A)  -2 
B)  0 
C)  2 
D)  4 B

Question 4

Which element is approximately 65 percent of sulfuric acid by weight?

Accepted Answer

A)  hydrogen 
B)  sulfur 
C)  oxygen 
D)  any of these 
A)  hydrogen 
B)  sulfur 
C)  oxygen 
D)  any of these

Question 5

Individuals,ages 19-70,should include at least 1000 mg of calcium in their daily diet.What is the minimum number of one-gram calcium supplement tablets you would need to take each day to meet this requirement if a tablet is 40% by mass calcium?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
A)  1 
B)  2 
C)  3 
D)  4

Question 6

Using whole numbers,determine the molecular weight of calcium hydroxide,Ca(OH)2.

Accepted Answer

A)  56 
B)  57 
C)  58 
D)  74 
A)  56 
B)  57 
C)  58 
D)  74

Question 7

Write the formula for a compound consisting of 3 sodium atoms,1 phosphorus atom,and 4 oxygen atoms.

Accepted Answer

A)  S3PO4 
B)  3NaP4O 
C)  Na3P2(O2) 
D)  Na3PO4 
A)  S3PO4 
B)  3NaP4O 
C)  Na3P2(O2) 
D)  Na3PO4

Question 8

The most accurate way to determine atomic mass is with a mass spectrometer.

Accepted Answer

A) True 
 B)False

Question 9

How many moles of hydrogen molecules (H2)would be required to produce two moles of hydrogen peroxide (H2O2)?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
A)  1 
B)  2 
C)  3 
D)  4

Question 10

The average relative mass of an ozone molecule is 48.0 u.An ozone molecule contains only oxygen atoms.What does this molecular weight indicate about the formula of the ozone molecule?

Accepted Answer

A)  It is monoatomic. 
B)  It is diatomic. 
C)  It is triatomic. 
D)  Impossible to determine 
A)  It is monoatomic. 
B)  It is diatomic. 
C)  It is triatomic. 
D)  Impossible to determine

Question 11

Which of the following pairs are about equal in mass?

Accepted Answer

A)  proton and electron 
B)  electron and neutron 
C)  proton and neutron 
D)  nucleus and surrounding electrons 
A)  proton and electron 
B)  electron and neutron 
C)  proton and neutron 
D)  nucleus and surrounding electrons

Question 12

Consider the representation shown below.It should be classified as

Accepted Answer

A)  an element consisting of 6 atoms. 
B)  a compound containing atoms of two elements. 
C)  a homogenous mixture of two elements. 
D)  a homogenous mixture of two compounds. 
A)  an element consisting of 6 atoms. 
B)  a compound containing atoms of two elements. 
C)  a homogenous mixture of two elements. 
D)  a homogenous mixture of two compounds.

Question 13

Which of the following has the largest mass?

Accepted Answer

A)  5.0 mol H2O 
B)  3.5 mol NH3 
C)  8.0 mol C 
D)  6.0 mol C2H2 
A)  5.0 mol H2O 
B)  3.5 mol NH3 
C)  8.0 mol C 
D)  6.0 mol C2H2

Question 14

The system of atomic mass units is based on

Accepted Answer

A)  assigning 12C as weighing exactly 12 u & comparing other elements to it. 
B)  measuring the true mass of each subatomic particle. 
C)  comparing the differences in protons and electrons. 
D)  viewing how atoms are affected by electromagnetic fields. 
A)  assigning 12C as weighing exactly 12 u & comparing other elements to it. 
B)  measuring the true mass of each subatomic particle. 
C)  comparing the differences in protons and electrons. 
D)  viewing how atoms are affected by electromagnetic fields.

Question 15

Why is CaO the symbol for calcium oxide instead of CAO?

Accepted Answer

A)  both can be the symbols for calcium oxide 
B)  both are incorrect;the symbol is cao 
C)  a capital letter means a new symbol 
D)  both are incorrect as the symbol should be CaOx 
A)  both can be the symbols for calcium oxide 
B)  both are incorrect;the symbol is cao 
C)  a capital letter means a new symbol 
D)  both are incorrect as the symbol should be CaOx

Question 16

What is the weight percentage of nitrogen in urea,CN2H4O?

Accepted Answer

A)  46.7 
B)  30.4 
C)  32.6 
D)  16.3 
A)  46.7 
B)  30.4 
C)  32.6 
D)  16.3

Question 17

You discover a new element which consists of two isotopes.The first isotope,243X (mass = 242.45 u)comprises 40.000% of the total.The second isotope,248X (mass = 247.11 u)accounts for the rest.What would be the average atomic mass for your new element?

Accepted Answer

A)  242.45 u 
B)  244.32 u 
C)  245.25 
D)  247.11 
A)  242.45 u 
B)  244.32 u 
C)  245.25 
D)  247.11

Question 18

Approximately,how many atoms of beryllium would be required to equal the mass of 10 atoms of aluminum?

Accepted Answer

A)  3 atoms of beryllium 
B)  10 atoms of beryllium 
C)  30 atoms of beryllium 
D)  4 atoms of beryllium 
A)  3 atoms of beryllium 
B)  10 atoms of beryllium 
C)  30 atoms of beryllium 
D)  4 atoms of beryllium

Question 19

The formula for dinitrogen monoxide is N2O.If a sample of the oxide was found to contain 0.0800 g of oxygen,how many grams of nitrogen would it contain?

Accepted Answer

A)  0.140 
B)  0.280 
C)  0.560 
D)  0.0700 
A)  0.140 
B)  0.280 
C)  0.560 
D)  0.0700

Question 20

Oxalic acid is found in many plants,like spinach and black tea.What is the mass of the carbon found in one mole of oxalic acid,H2C2O4?

Accepted Answer

A)  12.01 g of C 
B)  24.02 g of Cl 
C)  45.01 g of C 
D)  90.02 g of C 
A)  12.01 g of C 
B)  24.02 g of Cl 
C)  45.01 g of C 
D)  90.02 g of C

Exam 2: Atoms and Molecules

In naturally occurring samples,all elements exist as a mixture of isotopes.

The atomic mass number is a whole number and indicates a specific isotope of an element.

How many electrons are found around the species below?

Which element is approximately 65 percent of sulfuric acid by weight?

Individuals,ages 19-70,should include at least 1000 mg of calcium in their daily diet.What is the minimum number of one-gram calcium supplement tablets you would need to take each day to meet this requirement if a tablet is 40% by mass calcium?

Using whole numbers,determine the molecular weight of calcium hydroxide,Ca(OH)2.

Write the formula for a compound consisting of 3 sodium atoms,1 phosphorus atom,and 4 oxygen atoms.

The most accurate way to determine atomic mass is with a mass spectrometer.

How many moles of hydrogen molecules (H2)would be required to produce two moles of hydrogen peroxide (H2O2)?

The average relative mass of an ozone molecule is 48.0 u.An ozone molecule contains only oxygen atoms.What does this molecular weight indicate about the formula of the ozone molecule?

Which of the following pairs are about equal in mass?

Consider the representation shown below.It should be classified as

Which of the following has the largest mass?

The system of atomic mass units is based on

Why is CaO the symbol for calcium oxide instead of CAO?

What is the weight percentage of nitrogen in urea,CN2H4O?

You discover a new element which consists of two isotopes.The first isotope,243X (mass = 242.45 u)comprises 40.000% of the total.The second isotope,248X (mass = 247.11 u)accounts for the rest.What would be the average atomic mass for your new element?

Approximately,how many atoms of beryllium would be required to equal the mass of 10 atoms of aluminum?

The formula for dinitrogen monoxide is N2O.If a sample of the oxide was found to contain 0.0800 g of oxygen,how many grams of nitrogen would it contain?

Oxalic acid is found in many plants,like spinach and black tea.What is the mass of the carbon found in one mole of oxalic acid,H2C2O4?

Matter, measurements, and Calculations

Electronic Structure and the Periodic Law

Forces Between Particles

Chemical Reactions

The States of Matter

Solutions and Colloids

Reaction Rates and Equilibrium

Acids,bases,and Salts

Radioactivity and Nuclear Processes

Organic Compounds: Alkanes

Unsaturated Hydrocarbons

Alcohols, phenols, and Ethers

Aldehydes and Ketones

Carboxylic Acids and Esters

Amines and Amides

Carbohydrates

Lipids

Proteins

Enzymes

Nucleic Acids and Protein Synthesis

Nutrition and Energy for Life

Carbohydrate Metabolism

Lipid and Amino Acid Metabolism

Body Fluids

Filters

Using whole numbers,determine the molecular weight of calcium hydroxide,Ca(OH)₂.

How many moles of hydrogen molecules (H₂)would be required to produce two moles of hydrogen peroxide (H₂O₂)?

What is the weight percentage of nitrogen in urea,CN₂H₄O?

You discover a new element which consists of two isotopes.The first isotope,²⁴³X (mass = 242.45 u)comprises 40.000% of the total.The second isotope,²⁴⁸X (mass = 247.11 u)accounts for the rest.What would be the average atomic mass for your new element?

The formula for dinitrogen monoxide is N₂O.If a sample of the oxide was found to contain 0.0800 g of oxygen,how many grams of nitrogen would it contain?

Oxalic acid is found in many plants,like spinach and black tea.What is the mass of the carbon found in one mole of oxalic acid,H₂C₂O₄?