Year 8 Science · Unit 2 · Lesson 14

Patterns in the Periodic Table

Challenge Worksheet

Name

Date

Class

Learning Goals

Evaluate a claim about the usefulness of the periodic table using evidence from group patterns.
Distinguish between a useful organisational system and a system that merely reflects coincidence.
Propose a specific experiment that would test whether periodic patterns are real relationships.

Go Deeper

Evaluate the claim

Someone claims…

"The periodic table is just a convenient way to organise information, the patterns you see are coincidences, not real relationships. You could organise elements alphabetically by name and it would be just as useful for predicting properties. The fact that Group 1 metals all react with water is just a coincidence of how scientists chose to draw the table."

(a) What part of this claim is correct or at least understandable? (Hint: think about what 'organise' means and whether all organisations are equally useful.)

Challenge 2 marks

(b) What does the evidence from Group 1 (alkali metals) and Group 17 (halogens) show about whether the patterns are real relationships or coincidences? Use at least two specific examples in your answer.

Challenge 3 marks

(c) Describe one specific experiment that would disprove the claim that alphabetical ordering is just as useful as the periodic table for predicting properties. What would you test, what would you measure, and what result would show the periodic table is superior?

Challenge 3 marks

Show What You Know

1. The claim says you could organise elements alphabetically and it "would be just as useful." Astatine (At) comes before bromine (Br) alphabetically, but in the periodic table bromine is above astatine in Group 17. Using the halogen reactivity pattern, explain why the periodic table's arrangement gives you information that an alphabetical list cannot.

Challenge 3 marks

2. A scientist at the Australian Nuclear Science and Technology Organisation (ANSTO) needs to predict the properties of a newly synthesised element, oganesson (Og, atomic number 118), which sits in Group 18 at the bottom of the noble gases column. Using the group pattern and the argument about coincidence versus real relationship, what prediction would a periodic table allow, and why would an alphabetical list give you nothing useful? Write a fully developed response.

Challenge 4 marks

Wrap Up

In one sentence, what was the main idea of this lesson?