Unit 1: The Scientific Endeavour Flashcards

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1
Q

Qualitative Data

A

Involves the 5 senses
(sight, touch, smell, taste, hearing)

Usually descriptive or what you can observe with your 5 senses
(e.g. heavy, long, fast)

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2
Q

Quantitative Data

A

Involves senses and measurements taken using instruments

Has units, measurements or a numerical value
e.g. 2 ants, 500g, 50s

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3
Q

Observation

A
  • the act of attentive monitoring or perceiving, mediated through our five senses
  • the measurement, collection or recording of data, mediated through instruments, especially during an experiment
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4
Q

Inferences

A

• a logical conclusion that can possibly be derived based on the observations made.

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5
Q

Dependent

Variable

A

Variable Measured (VM)

A dependent variable is what you measure in an experiment and what is affected
during the experiment. The dependent variable is affected during the experiment.
The dependent variable responds to the independent variable.

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6
Q

Independent Variable

A

Variable Changed (VC)

An independent variable is the variable you have control over, what you can choose
and manipulate. It is usually what you think will affect the dependent variable.

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7
Q

Constants/ Fixed Variables

A

The factors within an experiment that are kept the same for all groups or trials in an attempt to reduce the influence of irrelevant variables.

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8
Q

Control Group

A

Controlled Variables (?)

The group in an experiment that receives the exact treatment as the experimental groups except it does not receive any change of the independent variable. It is the
group to which the experimental groups are compared.

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9
Q

Hypothesis

A

A tentative (i.e. not final and definite) and testable proposed explanation for an
observed phenomenon. It is based on observation and prior knowledge of the
system.
• It refers to only one dependent variable and one independent variable.
• It is written as a definite statement, and not a question.
• It is testable by experimentation.

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10
Q

Observations

A

The act of attentive monitoring or perceiving, mediated through our five senses and the measurement, collection or recording of data, mediated through instruments, especially during an experiment.

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11
Q

Inferences

A

A conclusion, based on facts, which a person perceives to be true.

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12
Q

Repeats

A

The replication of experimental and control groups is used to decrease the influence
of variations associated with the independent variable and researcher measurement error.

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13
Q

Accuracy

A

Readings are closest to real value but may not be close to one another.

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14
Q

Precision

A

Readings are closer to one another even if it is far from real value.

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15
Q

Parallax Error

A

Parallax Error
• Occurs when you did not read the marking of an instrument at eye level or did not read perpendicularly above the marking
• error in reading an instrument as a result of not viewing the measurement scale from the correct position.
• Unpredictable (human error)
• Can be corrected by reading the marking of an instrument at eye level or reading perpendicularly above the marking
• Factors that contribute to unpredictable errors include unpredictable environmental conditions and human reaction time in operating a stopwatch.

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16
Q

Zero Error

A
  • Occurs when a measuring instrument gives a reading not zero (when nothing is placed on it) when the true reading at that time is zero.
  • Consistent error = consistently inaccurate
  • Can be corrected by pressing the ‘tare’ button before placing something on the electronic balance or subtract (the amt that error causing) from final reading of mass
  • Occurs in measuring instruments e.g. weighing scale
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17
Q

Luminous Flame

A
  • flame is not as hot as non-luminous flame
  • yellowish-orange, blue
  • sooty
  • flickering and unsteady
  • more visible
  • obtain when air-hole is closed
  • flame burns less efficiently (incomplete combustion)
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18
Q

Non-Luminous Flame

A
  • flame is very hot
  • pale blue, blue
  • not sooty
  • steady
  • less visible
  • obtained when air-hole is open
  • flame burns more efficiently (complete combustion)
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19
Q

Why is a luminous flame yellow/orange?

A

It is due to the presence of carbon.

20
Q

Why is heating with a Bunsen burner usually carried out with an open instead of a closed air-hole?

A

Opening the air-hole will produce a non-luminous flame which is hotter and burns more efficiently than a luminous flame.

21
Q

What is obtained when the air-hole is closed?

A

Luminous Flame

22
Q

What is the colour of a luminous flame?

A

yellowish-orange, blue

23
Q

Which flame is sooty? (smoke like thing??)

How is soot produced?

A

Luminous Flame

Soot is produced when there is incomplete combustion / insufficient oxygen

24
Q

Which flame is flickering and unsteady?

A

Luminous Flame

25
Q

Which flame burns less efficiently? Why?

A

Luminous Flame

There is incomplete combustion/ insufficient oxygen

26
Q

Which flame is very hot?

A

Non-Luminous Flame

27
Q

Which flame is pale blue/ blue in colour?

A

Non-Luminous Flame

28
Q

Which flame is not sooty?

A

Non-Luminous Flame

29
Q

Which flame is steady?

A

Non-Luminous Flame

30
Q

Which flame is less visible?

A

Non-Luminous Flame

31
Q

Which flame burns more efficiently?

Why?

A

Non-Luminous Flame.

There is complete combustion/ sufficient oxygen.

32
Q

What is the inner blue zone of the non-luminous flame made up of?

A

Air and unburnt gas

33
Q

How does a strike-back flame occur?

A

A “strike back” flame may occur when the air-holes are fully open before you light up the Bunsen burner. There is too much air at the jet which results in the gas burning at the jet inside the barrel.

If your Bunsen burner has an accidental “strike back”, turn off the gas tap immediately and let the bunsen burner cool down before lighting it again.

34
Q

Which flame do you leave the bunsen burner in when it is temporarily not in use?

A

Luminous flame.

This is to make the flame visible so as to avoid accidentally burning one’s self.

35
Q

What is the function of the barrel in a Bunsen burner?

A

to raise the flame to a suitable height for burning

36
Q

What is the function of the collar in a Bunsen Burner?

A

to control the amount of air entering the burner by opening or closing the air-holes

to open or close the air hole

37
Q

What is the function of the gas tap of a bunsen burner?

A

to control the flow of gas to the bunsen burner

38
Q

what is the function of the air hole in a bunsen burner?

A

to allow air to enter the burner

to allow air (oxygen) to mix with gas fuel

39
Q

What is the function of the gas jet in a bunsen burner?

A

to enable the gas to rush out from the gas supply and to draw in air

40
Q

What is the function of the base in a bunsen burner?

A

to support the burner so that it will not topple

41
Q

How do you light a bunsen burner?

A
  1. close the air-hole
  2. hold a lighted match near the mouth of the barrel
  3. turn on the gas tap slowly (luminous flame)
  4. open the air-hole for heating (change to non luminous flame)
42
Q

Attitudes for science?

A
Curiosity
Perseverance
Positive approach to failure
Open-mindedness
Co-operation with others
Tolerance
Impartiality
Healthy scepticism
Integrity
Refusal to believe in superstitions
43
Q

What is the scientific method (steps)?

A
  1. Observe
  2. Record observations or measurements
  3. Suggest a hypothesis
  4. Test the hypothesis
  5. Infer from data
  6. Evaluate
44
Q

What are the safety rules when heating or mixing chemicals?

A

Wear goggles when heating or mixing chemicals.

Place flammable substances away from the naked flame.

Point the mouth of a test tube which is being heated away from yourself or your friends.

45
Q

What do you do when accidents occur?

A

Report all accidents, injuries, breakage and spillage to your teacher immediately.

If any chemical gets into your eyes or mouth, rinse your eyes or mouth with plenty of water and report the incident to your teacher.

46
Q

What are the steps involved in the scientific method to plan an experiment?

A
Make observations
↓
record observations or measurements
↓
suggest a hypothesis
↓
test the hypothesis
↓
infer from data
↓                             ↓
valid hypothesis   invalid hypothesis
↓                             ↓
theory                     go back to recording observations or measurements