Practical skills

Question 1

How to make results more reliable?

Answer 1

Repeat the experiement three times and find medium
- can find anomalous results and remove them
- if repeated readings are very different = unreliable

Question 2

why use burette over measuring cylinder?

Answer 2

higher resolutoin to maximise precision

Question 3

Issues that can effect the results of experiments

Answer 3

small sample size
experiment was not repeated
equipment not precise
certain variables werent controlled

Question 4

Bunsen burner safety

Answer 4

risk - can start a fire or burn someone
precaution - ensure loose clothing is kept away, hair tied up, flame should be on safety flame when not in use, heatproof mats placed beneah.

Question 5

hanging masses safety

Answer 5

risk - can fall and hit someone
precaution - stand away from it and wear protective, closed-toe shoes

Question 6

stretching a spring safety

Answer 6

risk - the spring may break and hit someone
precautions - wear googles to protect eyes from sharp metal and do not overload the spring

Question 7

accuracy

Answer 7

how close the readings are to the true value

Question 8

precision

Answer 8

how close together repeat readings are

Question 9

systematic error

Answer 9

fault with the equipment
from: not calibrating instruments properly, not taking the zero error into account ( when an instrument gives a false reading when the measured quantity is zero)

Question 10

graphs or bar charts

Answer 10

independent variable on the x axis and the dependent variable on the y axis

Question 11

what to use to measure small distances?

Answer 11

micrometer, screw gauge, digital caliper

Question 13

precautions when doing displacement water thing:

Answer 13

read the cylinder levels at the bottom of the meniscus
place eye level with surface in measuring cylinder
place container at a horizontal surface