Lesson 5: Flame Tests Revision Notes
Lesson Objectives
By the end of this revision sessions, you should be able to:
Grade C: Perform flame tests safely, following all safety guidelines to avoid accidents.
Grade B: Understand what a variable is and identify the change and measure variables in an experiment. A variable is something that can change and affect the results of the experiment.
Grade A: Describe control variables, which are the parts of the experiment that are kept the same to make sure the test is fair.
Introduction to Flame Tests
Flame tests are a way to see what metals are in different chemicals by burning them and looking at the colour of the flame. Each metal gives off a unique colour, helping scientists identify them.
Safety Measures for Flame Tests
Always wear safety glasses to protect your eyes from bright lights and sparks.
Keep loose clothing and long hair tied back to prevent accidents.
Make sure the Bunsen burner is on a heatproof mat and the rubber hose is securely attached to the gas tap.
Performing Flame Tests
Setting Up the Bunsen Burner: Use a yellow (safety) flame when you're not actively using the burner.
Preparing the Chemical: Dip a wire loop into one of the metal chemicals.
Burning the Chemical: Change the Bunsen burner to a roaring blue flame and put the wire in the edge of the flame.
Observing the Colour: Look at the colour of the flame, which shows which metal is present.
Repeating the Test: Try with different chemicals to see various flame colors.
Observing Flame Colors
Different metals produce different colours when burned. For example:
Potassium: Purple/Lilac
Calcium: Orange with some Red
Barium: Pale Green
Copper: Green/Blue
Sodium: Yellow
Strontium: Red
Lithium: Pink/Red
Understanding Variables in Flame Tests
Change Variable: The metal chemical we are testing (what we change).
Measure Variable: The colour of the flame (what we measure to see the effect of the change).
Control Variables: Things we keep the same in each test, like the amount of chemical or the type of flame, to ensure the test is fair and the results are reliable.
Test yourself
Keywords and Definitions
Flame Test: An experiment to see the colour of flame different metals produce, helping identify the metals.
Metal: A solid material that is typically hard, shiny, and conducts electricity and heat.
Variable: An element, feature, or factor that is likely to vary or change.
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