INTRODUCTORY CHEMISTRY
FREQUENTLY TESTED QUIZ AND EXAM
ANSWERS /GRADED A+
A cup of hot soup is initially at 85.4 °C, then cools by 33 °C over a period of 25 minutes.
What is the value that expresses the new temperature of the soup after 25 minutes
using the correct number of significant figures.
- answer-52 °C
A sample of iron is an example of a(n)
A) Element
B) Compound
C) Mixture
- answer-A) Element
A student has a body mass of 175.5 pounds. He steps onto a scale holding a 25.0-
pound barbell. Choose the value that expresses the combined mass of the student and
the barbell using the correct number of significant figures.
A) 200 lbs
B) 200.5 lbs
C) 200.50 lbs
D) 205 lbs
E) 150.5 lbs
- answer-B) 200.5 lbs
A theory is another word for a(n) _________.
A) model
B) law
C) measurement
D) experiment
- answer-Model
A thermometer reads 63.5 °C. What is the temperature in Fahrenheit?
- answer-146.3 °F or 146 °F
Accuracy definition help
- answer-Accuracy is when the average of the set of measurements is in the range of
uncertainty of the accepted value
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,An atom has nine protons and ten electrons. This makes it:
A) Nonstoichiometric
B) An ion
C) A cathode ray
D) An alpha particle
E) Neutrally charged
- answer-B) An ion
An atom of the isotope ¹³³Cs contains how many protons (p), neutrons (n), and electrons
(e)?
A) 55 p, 55 n, 55 e
B) 55 p, 78 n, 55 e
C) 133 p, 133 n, 133 e
D) 55 p, 133 n, 55 e
E) 133 p, 55 n, 55 e
- answer-B) 55 p, 78 n, 55 e
An unknown element is a mixture of isotopes ¹²⁹X and ¹³²X. The average atomic mass of
X is 130.79 amu. What is the percent abundance of ¹³²X?
- answer-59.7 % or 60%
An unknown element is a mixture of isotopes ¹⁵¹X (atomic mass = 150.99 amu) and ¹⁵³X
(atomic mass = 153.03 amu). The average atomic mass of X is 151.69 amu. What is the
percent abundance of ¹⁵³X?
- answer-34 %
An unknown element X has the following isotopes: ¹⁰X (20.00% abundant, atomic mass
= 10.01 amu) and ¹¹X (80.00% abundant, atomic mass = 10.99 amu). What is the
average atomic mass in amu of X?
- answer-10.794 amu
Arsenic is a toxic solid often used in the past as a component of pesticides. How many
electrons are present in a neutral atom of arsenic?
- answer-33
Atoms from which of the following pairs are most likely to form an ionic bond?
A) sodium and potassium
B) titanium and oxygen
C) sodium and barium
D) nitrogen and fluorine
- answer-B) titanium and oxygen
Barium sulfate (BaSO₄) is used in certain imaging techniques as a radiopaque contrast
media. Barium sulfate is a(n) ______.
A) molecular compound
B) molecular element
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, C) ionic compound
D) monatomic element
- answer-C) ionic compound
Classify each of the following compounds as ionic or covalent. Ca₃N₂
A) covalent
B) ionic
- answer-B) ionic
Classify each of the following compounds as ionic or covalent. CoBr₂
A) covalent
B) ionic
- answer-B) ionic
Classify each of the following compounds as ionic or covalent. HNO₃
A) covalent
B) ionic
- answer-A) covalent
Classify each of the following compounds as ionic or covalent. PI₅
A) covalent
B) ionic
- answer-A) covalent
Classify the following compounds as ionic or covalent (molecular): BaO, Fe₂O₃, ZnO.
A) Covalent, covalent, covalent.
B) Ionic, ionic, covalent.
C) Ionic, covalent, covalent.
D) Ionic, Ionic, Ionic.
- answer-D) Ionic, Ionic, Ionic.
Columns on the periodic table are known as
A) Periods
B) Halogens
C) Metals
D) Groups
E) Metalloids
- answer-D) Groups
Consider an atom of zirconium which has a mass number of 96. What is the chemical
symbol of this element?
A) Zr
B) Zi
C) Z
D) Zn
- answer-A) Zr
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FREQUENTLY TESTED QUIZ AND EXAM
ANSWERS /GRADED A+
A cup of hot soup is initially at 85.4 °C, then cools by 33 °C over a period of 25 minutes.
What is the value that expresses the new temperature of the soup after 25 minutes
using the correct number of significant figures.
- answer-52 °C
A sample of iron is an example of a(n)
A) Element
B) Compound
C) Mixture
- answer-A) Element
A student has a body mass of 175.5 pounds. He steps onto a scale holding a 25.0-
pound barbell. Choose the value that expresses the combined mass of the student and
the barbell using the correct number of significant figures.
A) 200 lbs
B) 200.5 lbs
C) 200.50 lbs
D) 205 lbs
E) 150.5 lbs
- answer-B) 200.5 lbs
A theory is another word for a(n) _________.
A) model
B) law
C) measurement
D) experiment
- answer-Model
A thermometer reads 63.5 °C. What is the temperature in Fahrenheit?
- answer-146.3 °F or 146 °F
Accuracy definition help
- answer-Accuracy is when the average of the set of measurements is in the range of
uncertainty of the accepted value
Please leave a 5-star review. Your review is my motivation. Success in your exams!!
,An atom has nine protons and ten electrons. This makes it:
A) Nonstoichiometric
B) An ion
C) A cathode ray
D) An alpha particle
E) Neutrally charged
- answer-B) An ion
An atom of the isotope ¹³³Cs contains how many protons (p), neutrons (n), and electrons
(e)?
A) 55 p, 55 n, 55 e
B) 55 p, 78 n, 55 e
C) 133 p, 133 n, 133 e
D) 55 p, 133 n, 55 e
E) 133 p, 55 n, 55 e
- answer-B) 55 p, 78 n, 55 e
An unknown element is a mixture of isotopes ¹²⁹X and ¹³²X. The average atomic mass of
X is 130.79 amu. What is the percent abundance of ¹³²X?
- answer-59.7 % or 60%
An unknown element is a mixture of isotopes ¹⁵¹X (atomic mass = 150.99 amu) and ¹⁵³X
(atomic mass = 153.03 amu). The average atomic mass of X is 151.69 amu. What is the
percent abundance of ¹⁵³X?
- answer-34 %
An unknown element X has the following isotopes: ¹⁰X (20.00% abundant, atomic mass
= 10.01 amu) and ¹¹X (80.00% abundant, atomic mass = 10.99 amu). What is the
average atomic mass in amu of X?
- answer-10.794 amu
Arsenic is a toxic solid often used in the past as a component of pesticides. How many
electrons are present in a neutral atom of arsenic?
- answer-33
Atoms from which of the following pairs are most likely to form an ionic bond?
A) sodium and potassium
B) titanium and oxygen
C) sodium and barium
D) nitrogen and fluorine
- answer-B) titanium and oxygen
Barium sulfate (BaSO₄) is used in certain imaging techniques as a radiopaque contrast
media. Barium sulfate is a(n) ______.
A) molecular compound
B) molecular element
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, C) ionic compound
D) monatomic element
- answer-C) ionic compound
Classify each of the following compounds as ionic or covalent. Ca₃N₂
A) covalent
B) ionic
- answer-B) ionic
Classify each of the following compounds as ionic or covalent. CoBr₂
A) covalent
B) ionic
- answer-B) ionic
Classify each of the following compounds as ionic or covalent. HNO₃
A) covalent
B) ionic
- answer-A) covalent
Classify each of the following compounds as ionic or covalent. PI₅
A) covalent
B) ionic
- answer-A) covalent
Classify the following compounds as ionic or covalent (molecular): BaO, Fe₂O₃, ZnO.
A) Covalent, covalent, covalent.
B) Ionic, ionic, covalent.
C) Ionic, covalent, covalent.
D) Ionic, Ionic, Ionic.
- answer-D) Ionic, Ionic, Ionic.
Columns on the periodic table are known as
A) Periods
B) Halogens
C) Metals
D) Groups
E) Metalloids
- answer-D) Groups
Consider an atom of zirconium which has a mass number of 96. What is the chemical
symbol of this element?
A) Zr
B) Zi
C) Z
D) Zn
- answer-A) Zr
Please leave a 5-star review. Your review is my motivation. Success in your exams!!
