GCSE Chemistry AQA Exam Flashcards

Flashcards for GCSE Chemistry AQA exam review.

In the context of risk assessment, what is a hazard?

A hazard is something that could potentially cause harm.

What is risk?

Risk is the chance that the hazard will cause harm.

What does it mean if an experiment is 'repeatable'?

Repeatable means that if the same person does an experiment again using the same methods and equipment, they'll get similar results.

What does it mean if an experiment is 'reproducible'?

Reproducible means that if someone else does the experiment, or a different method or piece of equipment is used, the results will still be similar.

What type of variable do you change in a lab experiment?

Independent Variable.

What is a dependent variable?

The variable you MEASURE when you change the independent variable.

What are control variables?

The variables that you KEEP THE SAME.

What causes random errors in an experiment?

The results of your experiment will always vary a bit because of RANDOM ERRORS - unpredictable differences caused by things like human errors in measuring.

What is it called if a measurement is wrong by the same amount every time?

Systematic Error.

What is the resolution of measuring equipment?

The smallest change a measuring instrument can detect.

What is a result that does not fit in with the rest?

ANOMALOUS RESULT.

What needs to be linear when drawing a bar chart?

The scale needs to be linear (there should be equal values for each division).

When should you use data to plot a graph?

If both variables are continuous (numerical data that can have any value within a range, e.g. length, volume, temperature) you should use a graph to display the data.

When looking at a graph, what does the gradient tell you?

The gradient (slope) of a graph tells you how quickly the dependent variable changes if you change the independent variable.

What is the formula for calculating the amount of a substance in moles?

moles = mass / molar mass.

What are three reasons for a correlation?

Chance, Linked by a 3rd variable, Cause.

When drawing conclusions, what are you limited to?

You can only conclude what the data shows and NO MORE.

How are the range and uncertainties related?

The larger the range, the less precise your results are and the more uncertainty there will be in your results.

What is Uncertainty in measurements?

Uncertainty is the Amount of Error Your Measurements Might Have.

What determines what type of atom something is?

It's the number of protons in the nucleus that decides what type of atom it is.

Why do alkali metals react similarly?

They all have one electron in their outer shell which makes them very reactive and gives them similar properties.

How did Mendeleev arrange elements in his table of elements?

Mendeleev put the elements mainly in order of atomic mass but did switch that order if the properties meant it should be changed.

What type of ions do halogens dorm when they bond with metals and what are they called?

Halogens from 1- ions called halides (F, Cl, Br and I-) when they bond with metals.