Ohio Graduation Test for Science – March 2006
Annotated Item 27
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 27.
Source: Ohio Department of Education
July 05
Ohio Graduation Test for Science – March 2006
Annotated Item 27
27. A neutral atom of silicon has
A.
12 electrons.
B.
13 electrons.
C. 14 electrons.
D. 15 electrons.
Commentary:
This multiple choice question asks students to determine the number of electrons in a neutral
atom of silicon using the partial periodic table provided. Students must understand the
arrangement of elements on the periodic table and what is represented by the atomic number of
an element. Students should recall that the atomic number of an element represents the
number of protons present in the atom. Students must further recall that electrically neutral
atoms contain equal numbers of protons (positively charged particles) and electrons (negatively
charged particles.) Students must accurately interpret the information presented on the partial
periodic table and note that silicon (Si) has an atomic number of 14. Answer choice C is correct
because silicon has 14 protons and is a neutral atom so it also has 14 electrons. All three
incorrect answer choices A, B, and D present numbers of electrons that do not represent a
neutral atom of silicon.
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 and the properties of neutral atoms to identify a valid scientific statement.
Performance Data:
The percent of public school students selecting answer choice C for question 27 on the March
2006 Ohio Graduation Test was 91%.
Keywords:
atom, electron, atomic number, proton
Source: Ohio Department of Education
July 05