Year 8 Science · Unit 2 · Lesson 13
Challenge Worksheet
Learning Goals
Find the mistake
A student wrote this answer
"Metals are always hard and shiny solids that conduct electricity well. Non-metals are soft, dull liquids or gases that don't conduct electricity at all. Metalloids are metals that have been mixed with non-metals. Silicon is a metalloid so it is made of metal atoms chemically bonded to non-metal atoms."
1. Identify at least three errors in the student's answer above. List each error clearly.
2. Write a corrected version for each error you identified. For each correction, explain in one sentence why the original statement is misleading.
1. Silicon is classified as a metalloid, yet it is the material that powers the entire modern electronics industry, from computer processors to solar panels. Explain the property of silicon that makes it so valuable, and explain why a pure metal or a pure non-metal could not do the same job. Use specific properties in your answer.
2. Mercury (Hg) is the only metal that is liquid at room temperature, and graphite (a form of carbon) is a non-metal that conducts electricity. A student claims: "These exceptions prove that the metal/non-metal classification system is unreliable and should be abandoned." Do you agree? Construct a scientific argument for or against this claim, using evidence from the lesson.
Wrap Up
In one sentence, what was the main idea of this lesson?