Deck 2: Atoms

Question 1

Which one of the following statements is NOT a correct statement of the Law of Conservation of Mass?

A) The mass of a system is dependent upon chemical reactions that may occur.
B) The mass of a system is conserved in a chemical reaction.
C) Matter cannot be created or destroyed.
D) Atoms are conserved in chemical reactions.

Answer 1

The mass of a system is dependent upon chemical reactions that may occur.

Question 2

Which of the following statements about atoms is NOT true?

A) Atoms are too small to be seen even with a microscope.
B) Atoms make up every material.
C) Atoms are the smallest particles that are characteristic of a given element.
D) No atoms have been synthesized by scientists.

Answer 2

No atoms have been synthesized by scientists.

Question 3

Leucippus and Democritus believed that all of the following statements about matter were true EXCEPT

A) Matter was made up of atoms.
B) Each type of matter had a distinctive size and shape.
C) Matter was continuous.
D) Substances are mixtures of different kinds of atoms.

Answer 3

Matter was continuous.

Question 4

Lavoisier performed many of the same experiments as his predecessors. The one thing that most distinguished Lavoisier's work was

A) the results.
B) the mass measurements.
C) the chemicals.
D) the glassware.

Question 5

The "father of modern chemistry" is

A) Boyle.
B) Lavoisier.
C) Mendeleev.
D) Proust.

Question 6

The Greek word atomos means

A) atom.
B) uncuttable.
C) invisible.
D) continuous.

Question 7

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

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

Question 8

Which philosopher believed that matter was continuous and was not made up of atoms?

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

Question 9

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?

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 10

Approximately how many elements occur naturally on Earth?

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

Question 11

A mixture containing 50 grams of carbon and 75 grams of oxygen is sealed in a flask. The total mass of the system is 225 grams. The flask is heated to cause the carbon and oxygen to react. The sealed flask is massed. What is the mass of the sealed flask?

A) 125 grams
B) 150 grams
C) 175 grams
D) 225 grams

Question 12

The amount of carbon on the earth, including the atmosphere,

A) is essentially constant.
B) is decreasing due to consumption of carbon based fuels, such as coal and petroleum.
C) is increasing due to plant and animal growth on the planet.
D) fluctuates dramatically with the seasons.

Question 13

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

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

Question 14

32 g of sulfur will react with 48 g of oxygen to produce 80 g of sulfur trioxide. If 16 g of sulfur and 100 g of oxygen are placed into a sealed container and allowed to react, what is the mass of the material in the container after the reaction is completed?

A) 40 g
B) 16 g
C) 100 g
D) 116 g

Question 15

Hydrogen peroxide decomposes into water and oxygen when exposed to heat or light. A tightly capped bottle of hydrogen peroxide is placed on a mass scale (a balance) and exposed to light for three weeks. The mass reading on the scale does not change. This is an example of

A) the Law of Conservation of Mass.
B) the Law of Definite Proportions.
C) the Law of Constant Composition.
D) the Law of Multiple Proportions.

Question 16

The amount of aluminum on the earth today relative to the amount 100 years ago when Al was first commercially extracted from bauxite, an aluminum containing ore,

A) is essentially the same.
B) is decreasing rapidly due to production of aluminum beverage containers.
C) is decreasing, but more slowly recently due to interest in recycling.
D) is actually increasing due to recycling efforts and more energy efficient production methods.

Question 17

Leucippus and Democritus proposed the "first" atomic view of matter. They arrived at this view based on

A) many experiments.
B) careful measurements.
C) philosophical and intuitive speculation.
D) All of the above contributed to their atomic view.

Question 18

32 g of sulfur will react with 48 g of oxygen to produce 80 g of sulfur trioxide. If 16 g of sulfur and 100 g of oxygen are placed into a sealed container and allowed to react, what is the mass of sulfur trioxide in the container after the reaction is completed?

A) 40 g
B) 16 g
C) 100 g
D) 116 g

Question 19

By definition, which of the following can be broken down into simpler substances?

A) compound
B) atom|ion
C) solid
D) liquid

Question 20

Lavoisier measured the mass of substances before and after chemical reactions and summarized his observations in a(n)

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

Question 21

The observation that 10 g of hydrogen gas always combines with 80 g of oxygen gas to form 90 g of water, even when there is more than 80 g of oxygen present in the reaction container, illustrates the Law of

A) Definite Proportions.
B) Multiple Proportions.
C) ideal gases.
D) excess reactants.

Question 22

When 28 g of nitrogen and 6 g of hydrogen react, 34 g of ammonia are produced. If 80 g of nitrogen react with 4 g of hydrogen, how much ammonia will be produced?

A) 22.6 g
B) 43 g
C) 50 g
D) 4 g

Question 23

Which discovery was NOT in conflict with Dalton's atomic theory?

A) the discovery of electrical charge
B) the discovery of the electron
C) the discovery of the element gallium
D) the discovery of the proton

Question 24

The ability to recycle aluminum (or glass, or plastic) is ultimately an illustration of

A) the Law of the Conservation of Mass.
B) the Law of Definite Proportions.
C) the ingenuity of chemists.
D) the Law of Multiple Proportions.

Question 25

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

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 26

2 g of sulfur will react with 3 g of oxygen to produce 5 g of sulfur trioxide. If 54 g of sulfur and 100 g of oxygen are placed into a sealed container and allowed to react, how much sulfur dioxide will be produced?

A) 54 g
B) 81 g
C) 135 g
D) 154 g

Question 27

Which of the following was NOT explained by Dalton's atomic theory?

A) the Law of Conservation of Mass
B) the Law of Multiple Proportions
C) the difference between isotopes of an element
D) the difference between elements and compounds

Question 28

Heptane is always composed of 84.0% carbon and 16.0% hydrogen. This illustrates the Law of

A) Conservation of Mass.
B) Definite Proportions.
C) Multiple Proportions.
D) all of the above

Question 29

Methane can be decomposed into two simpler substances, hydrogen and carbon. Therefore, methane

A) is a solid.
B) cannot be an element.
C) must be a mixture.
D) must have the formula CH₂.

Question 30

Which of the following can be broken down into simpler substances?

A) CO
B) Se
C) Mg
D) F

Question 31

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

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

Question 32

When 10.00 g of lead and 1.56 grams of sulfur react, 11.56 g of lead sulfide is produced. Suppose 30.00 g of lead and 1.56 g of sulfur are allowed to react. Analysis of the reaction mixture would show

A) 31.56 g of lead sulfide.
B) 34.68 g of lead sulfide.
C) 11.56 g of lead sulfide and 20.00 g of lead.
D) no reaction.

Question 33

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

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 34

Which of the following laws is NOT explained by Dalton's atomic theory?

A) the Law of Conservation of Mass
B) the Law of Definite Proportions
C) the Law of Multiple Proportions
D) the periodic law

Question 35

When added to a sealed flask and heated, 6.0 g of carbon and 16.0 g of oxygen react to form 22.0 g of carbon dioxide. How much carbon dioxide is formed when 24.0 g of carbon is reacted with 100.0 g of oxygen?

A) 40.0 g
B) 44.0 g
C) 88.0 g
D) 112.0 g

Question 36

When electricity is passed through molten potassium bromide, two simpler substances, potassium and bromine, are produced. Therefore, potassium bromide

A) cannot be an element.
B) must be a mixture.
C) has less mass than the resulting potassium and bromine do.
D) must have the formula PB.

Question 37

CO₂ always contains 3 g of C for every 8 g of O. This is an example of

A) Dalton's Atomic Theory.
B) Lavoisier's Law of Conservation of Mass.
C) Dalton's Law of Multiple Proportions.
D) Proust's Law of Definite Proportions.

Question 38

The Law of Definite Proportions was first stated by

A) Lavoisier.
B) Galileo.
C) Dalton.
D) Proust.

Question 39

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)

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

Question 40

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

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

Question 41

Perhaps the greatest triumph of Mendeleev's periodic table was

A) the use of rows and columns to organize the elements.
B) the ability to predict electron configurations of elements.
C) the use of atomic numbers as an organizing criterion.
D) the prediction of the existence of undiscovered elements.

Question 42

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

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

Question 43

Which set of compounds illustrates the Law of Multiple Proportions?

A) NH₃, PH₃, AsH₃
B) CH₃, CF₃, CCl₃
C) NH₃, N₂H₄
D) all of these

Question 44

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

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 45

One mole is of carbon is equal to

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 46

Although all parts (postulates) of Dalton's atomic theory are important, which one of the postulates is crucial to explain the observations summarized by the Law of Definite Proportions?

A) Matter is composed of atoms.
B) Atoms of the same element have the same properties.
C) Atoms combine with other atoms in fixed, whole number ratios to form compounds.
D) Atoms are very small.

Question 47

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

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

Question 48

Dalton explained the Law of Conservation of Mass by stating that atoms are neither created nor destroyed in a chemical reaction. Dalton's explanation is an example of a scientific

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

Question 49

Under conditions of limited oxygen, carbon burns to form carbon monoxide, a poisonous gas. In conditions with unlimited oxygen, carbon burns to form carbon dioxide. This illustrates the Law of

A) Conservation of Mass.
B) Definite Proportions.
C) different chemical reactions.
D) Multiple Proportions.

Question 50

Which one of the following is NOT part of Dalton's atomic theory?

A) Matter is composed of atoms.
B) Atoms of the same element have the same properties.
C) Atoms of different elements have different properties.
D) Atoms change into other atoms in chemical reactions.

Question 51

Mendeleev arranged elements in the periodic table primarily in order of their

A) atomic masses.
B) atomic weights.
C) both atomic weights and atomic numbers.
D) number of neutrons.

Question 52

The Periodic Table is helpful in all of the following endeavors but one. Which is the exception?

A) predicting formulas of compounds
B) predicting chemical reactivity of elements
C) predicting physical properties of elements
D) predicting monetary values of elements

Question 53

Which set of compounds illustrates the Law of Multiple Proportions?

A) CH₄, C₂H₆, C₃H₈
B) NO, NH₃, NH₄Cl
C) H₂O, H₂
D) all of these

Question 54

Nitrogen forms a number of different compounds with oxygen, depending upon the experimental conditions. This type of observation concerning the behavior of matter is summarized by

A) the Law of Conservation of Mass.
B) the Law of Definite Proportions.
C) the Law of Constant Composition.
D) the Law of Multiple Proportions.

Question 55

John Dalton discovered which of the following laws?

A) The Law of Conservation of Mass
B) The Law of Definite Proportions
C) The Law of Constant Composition
D) The Law of Multiple Proportions

Question 56

Atoms of the same element that have different masses are called

A) allotropes.
B) anions.
C) isotopes.
D) molecules.

Question 57

Which set of compounds illustrates the Law of Multiple Proportions?

A) SO₂, SO₃
B) N₂O, NO, NO₂
C) H₂O, H₂O₂
D) all of these

Question 58

The atomic masses for elements are

A) actual masses determined by weighing individual atoms.
B) relative masses determined by comparison with a standard reference.
C) the same as the atomic number.
D) unknown.

Question 59

How many grams of carbon are in 20.0 grams of CH₄?

A) 18.46 grams
B) 14.98 grams
C) 4.00 grams
D) 8.00 grams

Question 60

In plentiful air, 3.0 parts of carbon react with 8.0 parts of oxygen to form carbon dioxide. How much carbon is required to react with 1100 g of oxygen?

A) 600 g
B) 550 g
C) 2930g
D) 413 g

Question 61

Which of the following changes is NOT an example of green chemistry?

A) replacing mercury thermometers with alcohol thermometers
B) using large amounts of solvents such as benzene, which is a carcinogen
C) replacing energy from coal-fired power plants with energy from alternative sources
D) replacing lead in paint with titanium dioxide

Question 62

Substance A contains 80% carbon and 20% hydrogen. Substance B contains 83% carbon and 17% hydrogen. A and B are the same substance.

Question 63

All of the following are examples of molecules EXCEPT ________.

A) Si
B) CO
C) I₂
D) NO₂

Question 64

Assume that you have a new "triad" of elements (A, B and
C.) with similar properties. A is the smallest element and has a mass of 30 u. C is the largest element and has a mass of 90 u. The mass of B would be approximately ________ u.

A) 40
B) 45
C) 60
D) 80

Question 65

All of the following are molecules EXCEPT ________.

A) H₂
B) NO
C) H
D) O₃

Question 66

Which of the following is an example of green chemistry?

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 67

Leucippus and Democritus based their ideas about atoms on careful experimental results.

Question 68

Democritus thought that real substances were mixtures of various types of atoms.

Question 69

Mendeleev's periodic table organized elements in a systematic way. Which of the following attempted to arrange elements in a systematic way and can be considered a "precursor" of the modern periodic table?

A) Dalton's Atomic Theory
B) Dalton's Atomic Masses
C) Döbereiner's Triads
D) Berzelius's Atomic Weights

Question 70

Is it always possible to recycle and reuse materials?

A) Yes, because atoms cannot be destroyed in a chemical reaction.
B) Yes, because atoms can only be rearranged in a chemical reaction.
C) No, because atoms can be changed into other kinds of atoms.
D) No, if it is financially impractible to do it.

Question 71

In 1961, the reference for the atomic mass unit (amu or u) was changed from naturally occurring oxygen with a value of 16.000 u to one based on a single isotope of carbon (carbon-12). Why was it changed?

A) The atomic composition of oxygen varies depending upon its source.
B) Carbon-12 is more common than oxygen.
C) Carbon exists as only one isotope, carbon-12.
D) Carbon can combine with four atoms of hydrogen to form CH₄, methane, while oxygen only combines with two atoms of hydrogen to form water, H₂O.

Question 72

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

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

Question 73

What is the name of the Russian chemist who was a pioneer in the development of the periodic law?

A) Meyerovic
B) Mendeleev
C) Döbereiner
D) Berzelius

Question 74

Aristotle's idea that matter is continuous is still considered to be correct.

Question 75

For which of the following would recycling of iron NOT be practical?

A) old cars that are compressed in junkyards
B) steel beams that have been removed from a bridge
C) rust that flakes off a car body
D) wrought iron fences

Question 76

The Law of Constant Composition and the Law of Definite Proportions are different names for the same phenomenon.

Question 77

If drops of water are subdivided to the ultimately smallest drops possible, what is the smallest particle of water that retains the chemical and physical properties of water?

A) molecule
B) mixture
C) atom
D) micron

Question 78

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

Question 79

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

Question 80

When Mendeleev developed his periodic table, he placed the greatest emphasis on

A) the atomic number of the elements.
B) putting elements with similar properties in the same column.
C) leaving no holes or blank spaces in the table.
D) the melting points of the elements.