Scientific Endeavour

Question 1

Define accuracy.

Answer 1

Accuracy is when a reading is very close to the true value of the quantity when making a measurement.

Question 2

Define precision.

Answer 2

Precision is when multiple readings that are taken are very close to one another or are the same.

Question 3

What is qualitative data? List 2 examples.

Answer 3

Qualitative data is observations made using our senses.

Senses:
Sight, Hearing, Touch, Smell, Taste.

Question 4

What is quantitative data?

Answer 4

Quantitative data is measurements of numerical quantities of an object or phenomenon. (Things that CAN be counted)

Question 5

What is a zero error?

Answer 5

Zero error is a type of error when an instrument gives a non-zero reading when the measured quantity should be a zero. ( It is consistent. -> systematic error )

Question 6

What is a parallax error?

Answer 6

Parallax error is introduced into a measurement when the marking on an instrument is viewed from the wrong angle. ( It is consistent. -> systematic error )

Question 7

How does a strike back in a Bunsen burner occur?

Answer 7

It occurs when there is too much air, specifically oxygen, entering the air-hole.

Question 8

Give 2 differences between luminous and non-luminous flame.

Answer 8

A non-luminous flame occurs when the air-hole is opened whereas the luminous flame occurs when the air-hole is closed.
OR
A non-luminous flame burns steadily whereas a luminous flame burns unsteadily.
OR
A non-luminous flame is hotter than the luminous flame.
OR
A non-luminous flame has an outer blue flame whereas a luminous flame has an outer orange flame.

Question 9

What is an independent variable? ( Changed Variable )

Answer 9

It is the variable that you change during an experiment.

• There should only be one independent variable in your experiment.

Question 10

What is a dependent variable? ( Measured Variable )

Answer 10

It is the variable you observe and record during your experiment.

Question 11

What is a controlled variable? ( Constant Variable )

Answer 11

A variable that is needed to remain constant to ensure a fair test.

( there can be multiple controlled variables. )

Question 12

What is the S.I. Unit for mass? And what is an apparatus used to measure mass?

Answer 12

Kilogram. We can measure the mass of a substance using an electronic balance.

Question 13

What is the S.I. Unit for time? And what is an apparatus used to measure it?

Answer 13

Seconds (S) . Stopwatch.

Question 14

What is the S.I. Unit for volume? And what apparatus can you use to measure it?

Answer 14

Cubic metres (m 3). Measuring cylinder.

Question 15

What is the S.I. Unit for Temperature? And what is an apparatus used to measure it?

Answer 15

Kelvin (K). A laboratory thermometer.

Question 16

What is the S.I. Unit for length? And what is an apparatus used to measure it?

Answer 16

Metres (M) . Ruler/caliper.

Question 17

How do you remove the zero error when using an electronic balance? (To measure mass.)

Answer 17

By pressing the tare function to reset the digital display to zero before weighing.

Question 18

How do you read the volume of a liquid accurately and precisely?

Answer 18

By aligning your eyes to the liquid level to prevent parallax error.

Concave meniscus -> Read off the scale at the BOTTOM of the meniscus.

Convex meniscus -> Read off the scale at the TOP of the meniscus.

Question 19

How do you read the temperature of something by using a thermometer?

Answer 19

You must read it at eye level to prevent parallax error and the bulb of the thermometer must be fully submerged.

Question 20

What is the scientific process?

Answer 20

1. Investigation
2. Evaluation and reasoning
3. Developing explanations and solutions.