Chemistry Flashcards
What is a physical change?
A physical change is when something can be easily reversed and no new substance is formed.
What happens during a physical change?
The arrangement of particles changes but the particles do not change themselves.
Describe a physical change.
There is no change in mass or any permanent colour changes.
Are changes of state a physical or chemical change.
A physical change.
What is a chemical change
A chemical change is where a new substance is made and is not easily reversed.
In a chemical change what changes.
The particles themselves change.
What happens in a chemical change.
The mass could change, gas could be produced and / or a permanent colour change occurs.
What happens when zinc oxide is heated.
The original white powder turns yellow and upon cooling goes back to its original state. This is an example of a physical change.
What happens when copper carbonate is heated.
The green powder turns to a black powder and remains the same when cooling.
How do you know if your experiment is repeatable?
You get a similar result when you redo your experiment.
When others get the same result as you you know that your experiment is?
Reproducible.
What are anomalous results.
Anomalous results are odd results out.
How do you calculate the range.
The difference
How do you calculate the mean.
The mean result is calculated by excluding the anomalous results and adding them together. Then you divide them by the amount of numbers you added together. The mean result is closer to the actual answer than your experiment because it takes into account the affect of the random experimental errors
