Calculate the linear magnification of an image l

Calculate the linear magnification of an image l l l Three metric units that will be useful for this and all future microscope activities are the millimeter (mm) and micrometer (μm) and nanometer (nm) (*The micro symbol ‘μ’ looks like a ‘u’ with a longer tail in the front) 1 meter (m) = 1000 millimeters (mm) 1 millimeter (mm) = 1000 micrometers (μm) 1 micrometer (μm) =1000 nanometers(nm) m= 100 mm= 10 -3 μm = 10 -6 or 1 m or 0. 000001 m Let’s read the Magnification in Biology Sheet

Before we begin: l Note: l Numbers written like this: 1. 26 x 105 mean you move the decimal point to the right. In this case you move it 5 times: l 1. 26 x 105 = 126000. 0 1. 2 6 0 0 0. 0

The actual size of an object can be calculated using the same formula: Magnification = Image size Actual size of object MIA Therefore: AIM If an image is measured and found to have a length of 6 mm (6, 000 mm) and the magnification is 40, 000 then: Actual size of object = 6, 000 40, 000 = 0. 15 mm

Let’s look at the worked examples: l Worked example 1: Calculation of the magnification of a drawing l Worked example 2: Calculation of magnification and conversion of units l Worked example 3: Calculating magnification from a scale bar l When we are happy with this you will move onto some individual tasks

Task: 10 minutes 1. 2. 3. 4. 5. Read the calculating linear magnification sheet and go through worked example again THEN Complete the calculating linear magnification sheet 8 marks Cell Magnification practice 10 marks 2 x 2 mark exam questions 1 x 8 mark exam question ARE WE HAPPY NOW? ? ?

Plenary: l Complete the examination question 10 marks =10 minutes