Question 1

Which element is used in safety flares and fireworks because it burns so brightly?

Accepted Answer

A)  Potassium 
B)  Magnesium 
C)  Carbon 
D)  Chlorine 
A)  Potassium 
B)  Magnesium 
C)  Carbon 
D)  Chlorine

Question 2

A(n) ______________ is a substance composed of two or more elements chemically combined in a definite, fixed proportion by mass.

Accepted Answer

The answer of A(n) ______________ is a substance composed of...

Question 3

A metal alloy, such as brass, is

Accepted Answer

A)  a compound. 
B)  a heterogeneous mixture. 
C)  a homogeneous mixture. 
D)  an element. 
A)  a compound. 
B)  a heterogeneous mixture. 
C)  a homogeneous mixture. 
D)  an element.

Question 4

The hydroxide ion has a charge of

Accepted Answer

A)  1-. 
B)  zero. 
C)  1+. 
D)  2+. 
A)  1-. 
B)  zero. 
C)  1+. 
D)  2+.

Question 5

Over 99.9% of dry air at sea level is composed of the gases N2, O2, and ______________.

Accepted Answer

Question 6

About 99% by mass of Earth's atmosphere is composed of the two elements

Accepted Answer

A)  nitrogen and oxygen. 
B)  oxygen and carbon dioxide. 
C)  oxygen and silicon. 
D)  hydrogen and helium. 
A)  nitrogen and oxygen. 
B)  oxygen and carbon dioxide. 
C)  oxygen and silicon. 
D)  hydrogen and helium.

Question 7

An atom that has more electrons than protons is a ______________ ion.

Accepted Answer

A)  neutral 
B)  positive 
C)  negative 
D)  polyatomic 
A)  neutral 
B)  positive 
C)  negative 
D)  polyatomic

Question 8

When salt is dissolved in water, the salt is called the ______________.

Accepted Answer

The answer of When salt is dissolved in water, the...

Question 9

The elements of Group ______________ are the most chemically active metals.

Accepted Answer

The answer of The elements of Group ______________ are the...

Question 10

The major credit for the development of the periodic table goes to

Accepted Answer

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

Question 11

Nearly 100% by mass of Earth's core is composed of the two elements

Accepted Answer

A)  iron and nickel 
B)  aluminum and silicon 
C)  oxygen and aluminum 
D)  silicon and oxygen. 
A)  iron and nickel 
B)  aluminum and silicon 
C)  oxygen and aluminum 
D)  silicon and oxygen.

Question 12

A substance composed of two or more elements chemically combined in a definite, fixed proportion by mass is

Accepted Answer

A)  a molecule. 
B)  a compound. 
C)  an ion. 
D)  a mixture. 
A)  a molecule. 
B)  a compound. 
C)  an ion. 
D)  a mixture.

Question 13

An electrically neutral particle composed of two or more atoms chemically combined is called a(n) ______________.

Accepted Answer

The answer of An electrically neutral particle composed of two...

Question 14

The symbol for Krypton is

Accepted Answer

A)  Kr. 
B)  Sr. 
C)  Br. 
D)  Se. 
E)  Rb. 
A)  Kr. 
B)  Sr. 
C)  Br. 
D)  Se. 
E)  Rb.

Question 15

Chloroform can be broken down by chemical means but not by physical methods. Thus chloroform is

Accepted Answer

A)  a homogeneous mixture. 
B)  an element. 
C)  a compound. 
D)  a heterogeneous mixture. 
A)  a homogeneous mixture. 
B)  an element. 
C)  a compound. 
D)  a heterogeneous mixture.

Question 16

In 1869, a major event in the history of chemistry occurred; it was the

Accepted Answer

A)  discovery of the law of definite proportions. 
B)  discovery of the octet rule. 
C)  discovery of the law of conservation of mass. 
D)  development of the periodic table. 
A)  discovery of the law of definite proportions. 
B)  discovery of the octet rule. 
C)  discovery of the law of conservation of mass. 
D)  development of the periodic table.

Question 17

Which of the following Group 1A elements has the largest atom?

Accepted Answer

A)  Rb 
B)  Na 
C)  K 
D)  Li 
A)  Rb 
B)  Na 
C)  K 
D)  Li

Question 18

About 85% by mass of Earth's core is composed of the element(s)

Accepted Answer

A)  iron 
B)  nickel 
C)  oxygen. 
D)  silicon. 
E)  iron and nickel. 
A)  iron 
B)  nickel 
C)  oxygen. 
D)  silicon. 
E)  iron and nickel.

Question 19

Which of the following Group 1A elements has the smallest atom?

Accepted Answer

A)  Rb 
B)  Na 
C)  K 
D)  Li 
A)  Rb 
B)  Na 
C)  K 
D)  Li

Question 20

Atoms of which group of elements have seven electrons in the outer shell?

Accepted Answer

A)  Noble gases 
B)  Alkali metals 
C)  Alkaline earth metals 
D)  Halogens 
A)  Noble gases 
B)  Alkali metals 
C)  Alkaline earth metals 
D)  Halogens

Which element is used in safety flares and fireworks because it burns so brightly?

A(n) ______________ is a substance composed of two or more elements chemically combined in a definite, fixed proportion by mass.

A metal alloy, such as brass, is

The hydroxide ion has a charge of

Over 99.9% of dry air at sea level is composed of the gases N₂, O₂, and ______________.

About 99% by mass of Earth's atmosphere is composed of the two elements

An atom that has more electrons than protons is a ______________ ion.

When salt is dissolved in water, the salt is called the ______________.

The elements of Group ______________ are the most chemically active metals.

The major credit for the development of the periodic table goes to

Nearly 100% by mass of Earth's core is composed of the two elements

A substance composed of two or more elements chemically combined in a definite, fixed proportion by mass is

An electrically neutral particle composed of two or more atoms chemically combined is called a(n) ______________.

The symbol for Krypton is

Chloroform can be broken down by chemical means but not by physical methods. Thus chloroform is

In 1869, a major event in the history of chemistry occurred; it was the

Which of the following Group 1A elements has the largest atom?

About 85% by mass of Earth's core is composed of the element(s)

Which of the following Group 1A elements has the smallest atom?

Atoms of which group of elements have seven electrons in the outer shell?

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Atomic Physics

Nuclear Physics

The Chemical Elements

Chemical Bonding

Chemical Reactions

Organic Chemistry

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The Universe

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Atmospheric Effects

Structural Geology and Plate Tectonics

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Exam 11: Place and Time

Which element is used in safety flares and fireworks because it burns so brightly?

A(n) ______________ is a substance composed of two or more elements chemically combined in a definite, fixed proportion by mass.

A metal alloy, such as brass, is

The hydroxide ion has a charge of

Over 99.9% of dry air at sea level is composed of the gases N2, O2, and ______________.

About 99% by mass of Earth's atmosphere is composed of the two elements

An atom that has more electrons than protons is a ______________ ion.

When salt is dissolved in water, the salt is called the ______________.

The elements of Group ______________ are the most chemically active metals.

The major credit for the development of the periodic table goes to

Nearly 100% by mass of Earth's core is composed of the two elements

A substance composed of two or more elements chemically combined in a definite, fixed proportion by mass is

An electrically neutral particle composed of two or more atoms chemically combined is called a(n) ______________.

The symbol for Krypton is

Chloroform can be broken down by chemical means but not by physical methods. Thus chloroform is

In 1869, a major event in the history of chemistry occurred; it was the

Which of the following Group 1A elements has the largest atom?

About 85% by mass of Earth's core is composed of the element(s)

Which of the following Group 1A elements has the smallest atom?

Atoms of which group of elements have seven electrons in the outer shell?

Temperature and Heat

Waves and Sound

Optics and Wave Effects

Electricity and Magnetism

Atomic Physics

Nuclear Physics

The Chemical Elements

Chemical Bonding

Chemical Reactions

Organic Chemistry

The Solar System

Moons and Small Solar System Bodies

The Universe

The Atmosphere

Atmospheric Effects

Structural Geology and Plate Tectonics

Minerals Rocks and Volcanoes

Surface Processes

Geologic Time

Filters

Over 99.9% of dry air at sea level is composed of the gases N₂, O₂, and ______________.