KS3 Science Skills
Skills Key Words Write a definition for each of the key words listed below Key words Hypothesis Variable Prediction Method Hazard Precision Accuracy Repeatability Reproducibility Anomaly 2
1. Hazards You usually find a set of lab safety rules in a science lab. They are there for your safety! The drawing below shows a lab where there are no safety rules. 1. Circle all the things that are going wrong in this lab 2. Using your answers write a list of safety rules below: 3
1. Hazards Hazard symbols are used in the laboratory to show what dangers t look out for. Complete the table below to describe the hazard represented by the symbol. The first one has been done for you. HAZARD This will catch fire if it is near a flame. LABEL HAZARD LABEL Flammable Design your own hazard symbol in the final box and explain what hazard this symbol represents 4
2. Measurements and Scales In Science it is important that measurements are recorded accurately during a scientific investigation Look at the scales on the measuring cylinders below and write the reading underneath each scale. Colour in each thermometer so that it reads the temperature stated underneath 77 o C 32 o C 93 o C 24 o C 88 o C 5
3. Variables Variables are the things that we change, or decide not to change, in an experiment. In other words, they are the very things we are investigating! What is an independent variable? What is a dependent variable? What are control variables and why do we need them? For each of the experiments below. Identify the independent, dependent and control variable. Sarah wants to find out what material she should use to make the roof of her rabbit hutch waterproof so her rabbit stays dry. She has a range of materials and she puts a beaker with volume measurements to collect the water inside the hutch What is the independent variable? What is the dependent variable? What is the control variable? James is trying to design a soap-box go-kart to race down a big hill. He thinks that having bigger wheels will make the kart go faster. What is the independent variable? What is the dependent variable? What is the control variable? 6
4. Writing a Method What is a method? Why do we need a method when carrying out a scientific investigation? Read through these examples, and decide with whether you think they are bad/ok/good/very good/ amazing, why do you think this? Annotate the method to explain your reasoning. Example 1 Will water freeze faster or slower with the addition of sugar? Place two containers of equal amounts of water, one with sugar added, into the freezer. At intervals of 30 minutes, open the freezer to determine the status of each container. Continue until both have frozen. Write down the times that the containers were checked and when they each reached a fully frozen level. Example 2 Example 3 How does sunlight affect the growth of plant? Put a few plants in the window. Measure the height of the plant after a few days. Does coffee make you run faster? Firstly, I will select some participants, both of the same age, height, running ability and sex. This will make my results more controlled. I will then measure 100m, and ask both participants to run as fast as they can, I will time this in seconds and write the results in my results table. Both participants will then rest for 30 minutes. After the 30 minutes one of the runners will drink 100ml of standard coffee, and the other will have 100ml of water (with no coffee), they will then sit down for another 30 minutes, to give time for the coffee to work. After this time, both will run another 100m and I will time them (in s) and I will write this time in my results table. Finally, I will draw a bar graph of my results and compare the runner who had coffee before and after, as well as with the runner who did not have coffee. My independent variable is whether they had coffee or not, my dependent variable is the time it took them to run 100m. I kept everything else the same as much as I could. The safety precautions I took were to make sure my participants hand no health problems e.g. allergies, and I made sure the running area was clear of obstructions. 7
4. Writing a Method Using your knowledge of what makes a good method. Write out a simple method for making a cup of tea using the equipment/ingredients listed below: -Tea bag -Water -Spoon -Milk -Sugar -Cup -Kettle.. 8
5. Drawing a results table Tables can be used to present experimental results in science. Look at the results tables below. Rank the tables in order from best to worst. Temperature 20 100 109 106 30 77 69 85 40 54 62 55 50 42 40 38 60 29 25 24 20 100 109 106 30 77 69 85 40 54 62 55 50 42 40 38 60 29 25 24 Temperature 20 100 30 77 40 54 50 42 60 29 Temp ( o C) Average 20 100 109 106 315 30 77 69 85 77 40 54 62 55 57 50 42 40 38 40 60 29 25 24 26 Explain you reasoning. Temperature ( o C) 20 100 109 106 30 77 69 85 40 54 62 55 50 42 40 38 60 29 25 24 9
5. Drawing a results table Tables can be used to present experimental results in science. Tables can be used to show means (averages) or percentages. Complete the tables below to show the means and percentages for the experimental results Temp ( o C) mass (g) mass (g) mass (g) 20 2 5 3 30 7 9 10 40 12 12 11 Mean Mean is the sum of all the terms divided by the total number of terms Eye Colour No Students Percentage Brown 13 Blue 8 Green 4 To calculate a percentage: Eye colour X 100 Total No of Students 10
6. Plotting a graph A graph is a diagram that shows the connection between two or more things. A graph has two axes Horizontal axis (X axis): Independent variable Vertical axis (Y axis): Dependent variable A line or curve of best fit on a graph shows a pattern or trend in results. Plot a graph to show the results in the table below: Temperature of water being heated ( minutes) Temperature (Celsius) 0 20 1 40 2 60 3 70 4 80 5 85 6 90 7 95 Explain the trend/relationship shown in the graph: 11