The method and the results are on the periodic table lab. Do the analysis yourself first, then check the answers below.
Quick answer: An element is a pure substance made of only one kind of atom, written with a symbol such as Na or Fe. These answers go with the grade 8 science lab on periodic table: the graph, the calculations, the uncertainties and the conclusion explained, for all 7 analysis questions.
Model answers follow the sample results in the table. Your own readings may differ a little, but the pattern of metals conducting and non-metals crumbling should be the same.
Copper, iron and aluminium are shiny, light the lamp brightly and flatten or bend: probably metals. Graphite, chalk and wax are dull, conduct poorly or not at all, and crumble or dent: probably not metals.
Question 2 Percentage that conduct
Conductors: copper, iron, aluminium, graphite = 4 of 6, which is 4 ÷ 6 × 100 = 67 %. Metals among them: 3 of 4 = 75 %.
Question 3 The graphite exception
Conduction alone is not a perfect test, because graphite is a non-metal that conducts. Use several properties together. One test is not enough.
Question 4 Using the magnet
Only iron was attracted, so iron is magnetic. Copper and aluminium are metals that are not magnetic, so magnetism is not a test for all metals.
Question 5 Elements and compounds
They are not elements: chalk is a compound of calcium, carbon and oxygen, and wax is made of compounds. The periodic table lists elements only.
Question 6 Anomalous results
The nail may have been rusty or painted at the contact point, or the clips may have been loose. Clean the nail with sandpaper, tighten the clips and test again. Poor contact is the likely cause.
Question 7 Improving the test
Add an ammeter in series with the lamp and record the current in amps for each sample. Use an ammeter.
