Ohio Graduation Test for Science– March 2005
Annotated Item 35
Standard and Benchmark Assessed:
Standard:
Benchmark:
Physical Sciences
A. Describe that matter is made of minute particles called atoms and atoms are
comprised of even smaller components. Explain the structure and properties of
atoms.
Multiple Choice Question:
Use the partial periodic table to answer question 35.
35.
Suppose scientists discovered four new elements (W, X, Y, Z) while studying rock and soil
samples brought back from a Mars mission. Which Lewis dot structure represents an
element that should be placed in column VIIA (17) of the periodic table?
Source: Ohio Department of Education
July 05
Ohio Graduation Test for Science– March 2005
Annotated Item 35
Commentary:
This multiple choice question asks students to determine which Lewis dot structure represents a
newly discovered element that should be placed in column VIIA (17) of the periodic table.
Students must understand the concept of periodicity and the arrangement of elements on the
periodic table. Students must know that repeating patterns of physical and chemical properties
of elements identify them as families, found in columns. One of these repeating patterns is the
number of electrons occupying the outermost (valence) shell of the atom. Elements that have
the same number of valence electrons occupy the same column of the periodic table. Students
must apply prior knowledge that Lewis dot structures symbolize an element surrounded on four
sides (top, bottom, left and right) by the number of valence electrons found in a neutral atom of
the element. The electrons here are represented by dots. Students must know or be able to
determine (using periodicity, atomic number, or knowledge related to how electron shells fill)
that elements in column VIIA (17) have seven electrons in their outermost shells. Answer A is
the correct choice because seven dots surround the symbol W indicating that this new element
has seven valence electrons just like other elements (fluorine (F) and chlorine (Cl)) located in
column VIIA (17) of the periodic table. All three incorrect answer choices, B, C and D, present
Lewis dot structures that contain fewer or more than seven dots surrounding any of the other
symbols.
The question is classified as Recalling/Identifying Accurate Science because this task requires
students to recall previously learned facts regarding the structure and arrangement of the
periodic table to identify a valid model.
Performance Data:
The percent of public school students selecting answer choice A for question 35 on the March
2005 Ohio Graduation Test was 41%.
Keywords:
Lewis dot structure, periodicity, periodic table, electron
Source: Ohio Department of Education
July 05