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Worksheets16.2 QUIZ — Form B: Atomic Mass, Isotopes & the Periodic Table
Total questions: 20
Worksheet time: 10mins
Multiple Choice Identify the choice that best completes the statement or answers the question. Write your answer on the line provided. Radioactive decay occurs because
electrons escape from the atom
neutrons naturally disappear
the nucleus is unstable
atomic mass decreases over time
Multiple Choice Identify the choice that best completes the statement or answers the question. Write your answer on the line provided. Which statement best defines half-life?
The time needed for all atoms in a sample to decay
The time it takes for half of a radioactive sample to decay
The mass lost during radioactive decay
The number of neutrons lost per second
Multiple Choice Identify the choice that best completes the statement or answers the question. Write your answer on the line provided. A radioactive isotope has a half-life of 5 years. What fraction of the original sample remains after 15 years?
1/2
1/3
1/8
1/16
Multiple Choice Identify the choice that best completes the statement or answers the question. Write your answer on the line provided. Why are half-lives useful to scientists studying Earth’s history?
They vary depending on temperature
They allow scientists to estimate age over long periods of time
They occur instantly
They only apply to living systems
Multiple Choice Identify the choice that best completes the statement or answers the question. Write your answer on the line provided. Which statement correctly describes radioactive isotopes used in medicine?
They destroy healthy cells only
They are unstable and emit radiation that can be detected
They remain permanently inside the body
They are chemically inactive
Multiple Choice Identify the choice that best completes the statement or answers the question. Write your answer on the line provided. Atomic mass is described as a weighted average because
all isotopes contribute equally
heavier isotopes contribute more regardless of abundance
more abundant isotopes influence the value more
electrons are included in the calculation
Multiple Choice Identify the choice that best completes the statement or answers the question. Write your answer on the line provided. An element has three naturally occurring isotopes. Which isotope will most strongly affect the atomic mass listed on the periodic table?
The isotope with the greatest mass
The isotope with the greatest abundance
The isotope with the most neutrons
The radioactive isotope
Multiple Choice Identify the choice that best completes the statement or answers the question. Write your answer on the line provided. Why does the atomic mass of an element usually not equal a whole number?
Atomic mass includes electrons
Isotopes decay over time
Atomic mass is a weighted average of isotopes
Neutrons vary in size
Multiple Choice Identify the choice that best completes the statement or answers the question. Write your answer on the line provided. Which comparison between atomic mass and mass number is correct?
Atomic mass refers to one isotope; mass number refers to all isotopes
Atomic mass is always larger than mass number
Mass number applies to a single isotope
Mass number is found on the periodic table
Multiple Choice Identify the choice that best completes the statement or answers the question. Write your answer on the line provided. An element’s atomic mass is closest to one isotope’s mass. What does this suggest?
That isotope is radioactive
That isotope has the highest atomic number
That isotope is the most abundant
That isotope has the most protons
Multiple Choice Identify the choice that best completes the statement or answers the question. Write your answer on the line provided. Döbereiner’s early contribution to the periodic table involved
arranging elements by atomic number
grouping elements with similar properties into triads
predicting undiscovered elements
organizing elements into periods
Multiple Choice Identify the choice that best completes the statement or answers the question. Write your answer on the line provided. Newlands’ Law of Octaves stated that
elements should be grouped in threes
properties repeat every eight elements when ordered by mass
atomic number determines element properties
gaps should be left for unknown elements
Multiple Choice Identify the choice that best completes the statement or answers the question. Write your answer on the line provided. Why was Newlands’ system not completely successful?
He arranged elements incorrectly by atomic number
The repeating pattern did not work for all elements
He included isotopes
He ignored chemical properties
Multiple Choice Identify the choice that best completes the statement or answers the question. Write your answer on the line provided. What made Mendeleev’s periodic table different from earlier attempts?
It was arranged by atomic number
It included electrons
It left gaps for undiscovered elements
It removed transition metals
Multiple Choice Identify the choice that best completes the statement or answers the question. Write your answer on the line provided. Mendeleev left gaps in his periodic table because he
had incomplete data
expected new elements to be discovered
wanted consistent row lengths
believed some elements were unstable
Multiple Choice Identify the choice that best completes the statement or answers the question. Write your answer on the line provided. Which scientist corrected problems in Mendeleev’s table by using atomic number?
Döbereiner
Newlands
Moseley
Dalton
Multiple Choice Identify the choice that best completes the statement or answers the question. Write your answer on the line provided. The modern periodic table is arranged by atomic number because
atomic number changes over time
atomic number reflects proton count
atomic mass is unreliable
isotopes determine placement
Multiple Choice Identify the choice that best completes the statement or answers the question. Write your answer on the line provided. Elements in the same group on the periodic table generally
have the same atomic mass
have similar chemical properties
have the same number of neutrons
are radioactive
Multiple Choice Identify the choice that best completes the statement or answers the question. Write your answer on the line provided. Periods on the periodic table are best described as
vertical columns
groups with similar properties
horizontal rows
sets of isotopes
Multiple Choice Identify the choice that best completes the statement or answers the question. Write your answer on the line provided. Which statement best summarizes why the modern periodic table is effective?
It is based on atomic mass
It groups elements randomly
It reflects repeating patterns based on atomic number
It focuses only on metals
