Practical and Math Skills

• A good result should be?

  precise

  valid

  accurate

  repeatable
• How many variables are there?

  2 and they are dependent and independent variables.
• A dependent variable

  the variable that you measure
• Independent variable

  The variable that you change
• other variables other than the independent and independent should be ..

  control variables.
• Precise results are sometimes referred to as reliable results.
• What is the role of the negative control?

  To check that only the independent variable is affecting the dependent variable.
• What is the role of the positive control?

  they show what a positive result of the experiment should look like, to check that it is possible.
• Taking several repeat measurements and calculating the mean...

  could reduce the effect of random error.
• Why is carrying out repeats important?(large sample size)

  reduces the likelihood that the results are due to chance.
• wearing gloves, apron, eye protection are important when conducting an experiment.
• Dangers in an experiment

  hazardous chemicals, naked flames, or microorganisms.
• Who is at risk from dangers in a lab?😱

  lab partner or anyone in the room or building.😨
• What can be done to reduce risks in the lab

  wearing gloves

  keeping flammable chemicals away from naked flames

  using aseptic techniques.
• Ethical issues😟

  When using living animals in an experiment, treat them with respect; handle them carefully.
• 👩‍⚕️👨‍⚕️Scientists use statistical tests for what purpose?🤔

  to figure out if a result is due to chance or not.👌
• Carrying out an Experiment😀

  Make sure to use the correct apparatus and techniques; measure and read volumes the right way

  Water baths should be heat up before you start the experiment. use a thermometer to check the temperature of the water baths to make sure that it doesn't change.

  Data loggers are used to record data, it can be used when measuring ph and temperature.
• Recording data 😁

  when the results are obtained, its a good idea to draw a table to record the results of your experiments on.

  The units should be in the same columns as the heading.
• If you're recording your data as decimals, make sure to do it to a consistent number of decimal places.(●'◡'●)
• You could process your data.....💭

  by calculating the mean

  by calculating the range
• An average means the mean value
• Doing repeats makes it easier to spot anomalous results😉
• Standard deviation😛

  It tells you how values are spread about the mean rather than

  just the total spread of data. 🤯
• Median🔢

  The middle number in a set of numerical order.
• Mode🦣

  the highest occurring number in a set of numbers.
• Percentages(%)

  divide X by Y and multiply by 100
• Percentage changes (%)

  Final value- original value

  ------------------------ * 100

  original value
• Percentage change can be either positive or negative.
• Ratios

  Divide both sides by the same number to its simplest form.
• Rounding significant figures

  A significant figure is the first digit that isn't zero.When the last significant figure is less than one, you should round it down but when it is higher than five, you should round it up.
• Standard form

  changing numbers that have lots of zeros into a more manageable value. e.g, 1000000 becomes 1*10^6