1A2 Experiments and the Scientific Method Flashcards

Describe how the scientific method guides experimentation. Differentiate between qualitative and quantitative data, and understand scientific notation and hypothesis testing.

1
Q

What is a standard unit?

A

The most commonly used unit of measurement that is standardized for everyone to have the same understanding of size, weight, and other properties.

Standard units of measurement are fixed values that cannot change.

Examples of systems that utilize standard units include: US Customary System and Internal System of Units (SI system).

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2
Q

What is the US Customary System of measurement?

A

A measurement system primarily used in the U.S., including units for length, weight, volume, and temperature, widely applied in daily life, industry, and commerce.

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3
Q

What is the SI System of measurement?

A

An international system of measurement that utilizes the metric system.

The world’s most widely used system of measurement

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4
Q

What are the basic units of measure for length in the U.S. Customary System?

A
  • Inch
  • Foot
  • Yard
  • Mile
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5
Q

What are the basis units of measure for length in the Metric System?

A
  • Millimeter
  • Centimeter
  • Meter
  • Kilometer

SI base unit for length is the meter.

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6
Q

What are the basic units of measure for weight in the U.S. Customary System ?

A
  • Ounces
  • Pounds
  • Tons
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7
Q

What are the basic units of mass in the Metric System

A
  • Grams
  • Kilograms
  • Tons

SI base unit for mass is the kilogram

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8
Q

What are the standard units of time worldwide?

A
  • seconds
  • minutes
  • hours
  • days
  • weeks
  • months
  • years

Time is measured the same way no matter where you are in the world.
The SI base unit for time is the second.

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9
Q

What are the standard units of volume in the U.S. Customary System?

A
  • Cups
  • Pints
  • Quarts
  • Gallons
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10
Q

What are the standard units for volume in the metric system?

A

Liter

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11
Q

What are the seven SI Base Units?

A
  • Standard Unit of Length: meter (m)
  • Standard Unit of Time: second (s)
  • Standard Amount of Substance: mole (mole)
  • Standard Electric Current: ampere (A)
  • Standard Unit of Temperature: kelvin (K)
  • Standard Unit of Luminous Intensity: candela (cd)
  • Standard Unit of Mass: kilogram (kg)
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12
Q

What is the difference between mass and weight?

A
  • Mass is the amount of matter in a material.
  • Weight is the measure of the gravitational pull on an object.

The SI unit for measuring force is a Newton, named after Isaac Newton.

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13
Q

What is mass?

A

The amount of matter in a material.

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14
Q

What is weight?

A

The measure of the gravitational pull on an object.

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15
Q

What is the SI unit for measuring force?

A

Newton

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16
Q

What unit is used to measure force, including weight, in the metric system?

A

Newtons

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17
Q

What is dimensional analysis used for?

A

Dimensional analysis is used to change one unit to a different unit through a conversion factor that is an equalty.

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18
Q

What happens when you multiply fractions with the same units in the numerator and denominator?

A
  • They can cancel out.
  • Simplifying the fraction.
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19
Q

What is a conversion factor in dimensional analysis?

A

A ratio of two different equivalent quantities expressed with different measurement units.

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20
Q

How can multi-step unit conversion problems be solved?

A

By setting up fractions using conversion factors to cancel out unwanted units.

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21
Q

What should you remember when using dimensional analysis and conversion factors?

A

To set up the equivalency ratio so that the unwanted unit is canceled, and the desired unit remains.

This is essential for accurate problem-solving.

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22
Q

What are the conversion formulas for weight to mass between the US system and the metric system?

A
  • lb to kg: kg = lb / 2.2046
  • kg to lb: lb = kg * 2.2046
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23
Q

What are the conversion formulas for temperature between the US system and the metric system?

A
  • F to C: C = (F - 32) * 5/9
  • C to F: F = (C * 9/5) + 32
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24
Q

What are the conversion formulas for distance between the US system and the metric system?

A
  • mi to km: km = mi / 0.6214
  • km to mi: mi = km * 0.6214
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25
How do you convert 70 kilograms to pounds using the conversion formula?
154.32 pounds ## Footnote 70kg * 2.2046 lbs = 154.32 lbs 1 kilogram is equal to 2.2046 pounds. By multiplying 70 kg by 2.2046 lbs you get 154.32 pounds
26
How do you convert 150 pounds to kilograms using the conversion formula?
68.04 kilograms ## Footnote 150 lbs/2.2046 kg = 68.04 kilograms 1 kilogram is equal to 2.2046 pounds. By dividing 150 pounds by 2.2046 kg you find that there are 68.04 kg
27
What is the formula to *convert* from **degrees Fahrenheit to degrees Celsius**?
C = (F - 32) * 5/9 ## Footnote The formula involves subtracting 32 from the Fahrenheit temperature, multiplying by 5, and then dividing by 9.
28
How do you convert 98.6 degrees Fahrenheit to Celsius using the conversion formula?
37 degrees Celsius ## Footnote Subtract 32 from 98 degrees fahrenheit to get 66.6. Then multiply 66.6 by 5/9 to give you 37 degrees celsius.
29
What is the formula to *convert* from **Celsius to Fahrenheit**?
F = (C * 9/5) + 32 ## Footnote To convert from Celsius to Fahrenheit, multiply by degrees celsius by 9, divide by 5, and then add 32 to get degrees fahrenheit.
30
How do you convert 27 degrees Celsius to Fahrenheit using the conversion formula?
80.6 degrees Fahrenheit ## Footnote Multiply 27 degrees celsius by 9, then divide the answer by 5 to get 48.6. Then add 32 to 48.6 to get 80.6 degrees fahrenheit.
31
How do you **convert** from *kilometers to miles*?
mi = km * 0.6214 | 1 mile = 1.609 km ## Footnote To convert kilometers to miles, multiply the kilometers by 0.6214.
32
What is the relationship between 1 hour and 60 minutes in dimensional analysis?
* 1 hour = 60 minutes * 60 minutes = 1 hour
33
How do you convert 2.45 hours into minutes using dimensional analysis?
Multiply by 60 minutes by 2.45 hour to get 147 minutes | 1 hour = 60 minutes ## Footnote 2.45 hr x (60 min/1hr)= 147 minutes
34
What are **significant figures**?
The number of digits in a measured quantity that aids in the value's degree of accuracy and precision. ## Footnote Commonly used in the sciences especially chemistry and physics.
35
What are the general rules for determining significant figures?
* All non-zero digits are significant. * All zeros in between non-zero digits are significant. * All zeros before the first non-zero digit are NOT significant. * All zeros to the right of non-zero digits with decimals are significant. * All zeros after a non-zero non-decimal number are NOT significant.
36
What are the significant figure rules for **multiplication/division**?
The final answer will follow the factor's significant figures with the least number of significant digits. ## Footnote Example: 1000/98.3= 10.17293997. There is only 1 significant figure in 1000.Therefore the answer will rounded to 10.
37
What are the significant figure rules for **addition/subtraction**?
The final answer should be rounded to the same number of decimal places as the measurement with the least number of decimal places. ## Footnote Example: 1230+17=1247. While 1230 has 3 significant figures, 17 only has 2 meaning that when we add them together our answer will be rounded to 1250 to show the correct amount of significant figures.
38
What is the rule for **rounding significant figures**?
After determining the significant figures, when the number following the last significant digit is five or higher, round up by adding a 1 to the last number. ## Footnote Example: 32.67 would be rounded to 32.7
39
Give an example of all non-zero digits being significant.
* 1,234: 4 significant figures * 1.23: 3 significant figures
40
Give an example of all zeros before the first non-zero digit not being significant.
* 0.0000034: 2 significant figures; all zeros before 3 are not significant * 0.04: 1 significant figure; all zeros before 4 are not significant ## Footnote Zeros are just place holder as they become superfluous when the numbers are converted to scientific notation. (example: 0.0000034 = 3.4 x 10 ^ -6)
41
Give an example of all zeros after a non-zero non-decimal number not being significant.
* 12,000: 2 significant figures; the trailing zeros are not significant * 20,310: 4 significant figures; the zero after 1 is not significant, but the zero between 2 and 3 is significant
42
What are the *three parts* of scientific notation?
* The coefficient * The base * The exponent
43
What is the purpose of **scientific notation**?
It is a way of representing very large or very small numbers. ## Footnote When converting standard notation to scientific notation, move the decimal to the left or right until there is one non-zero integer on its left.
44
What is the rule for converting very large numbers to scientific notation?
Move the decimal to the left until there is one non-zero integer on its left. You then multiply by ten to the power of the number you moved it to the left. ## Footnote Example: 56,000,000 would be 5.6 x 10^7
45
What is the rule for converting very small numbers to scientific notation?
Move the decimal to the right until there is one non-zero integer on its right. You then multiply by ten to the *negative* power of the number you moved it to the right. ## Footnote Example: 0.0045 would be 4.5 x 10^-3
46
How is 154,050,600 written in scientific notation with two significant figures?
1.5 x 10^8 ## Footnote The final answer is 1.5 x 10^8 with two significant figures.
47
What type of information is based on observation but not directly measured and recorded numerically?
**Qualitative** | Qualitative=Quality ## Footnote Qualitative information is based on observation obtained through our senses but not directly measured numerically. *color, taste, feelings*
48
What type of information is based on a measurement and reported numerically?
**Quantitative** | Quantitative=Quantity ## Footnote Quantitative information is based on a measurement and reported numerically.
49
What is the difference between **qualitative** and **quantitative** observations?
* **Qualitative observations** describe characteristics. * **Quantitative observations** are based on measurements and reported numerically.
50
What is **precision**?
Refers to how close multiple measurements of the same value fall. ## Footnote The precision of a measuring instrument refers to the smallest repeatable digit it can measure to.
51
How is **precision** measured?
By assessing a sample's standard deviation or spread of responses. ## Footnote High Standard Deviation = Low precision Low Standard Deviation = High precision
52
What is **standard deviation**?
A measurement of how widely spread a data set is. ## Footnote Can help determine the precision of a measurement.
53
What are precision errors caused by?
* Random errors * Personal errors
54
How is **accuracy** measured in scientific sampling?
How close values are to the true population value. ## Footnote Accuracy can be measured with percent error which determines the percentage of error between the sample's measured observation and the true measure of the population.
55
What is the difference between **accuracy** and **precision**?
* **Accuracy** refers to how close a measurement is to the 'true' value. * **Precision** is the agreement of repeated measures.
56
What is an example of low accuracy and high precision?
When measured values are close together but far from the true value, such as an uncalibrated scale showing consistently higher values.
57
What is the purpose of an experimental design?
To test a hypothesis through a series of steps. ## Footnote The purpose is to create controlled conditions for an experiment to limit outside interference and form a conclusion based on the hypothesis. The scientific design process utilizes the scientific method to test a hypothesis.
58
What are the **steps** of the scientific method?
* Observe * Question * Research * Create a hypotheses * Create an experiment * Collect and analyze data * Draw a conclusion
59
What are **3 rules** that should be followed in order to design a good experiment?
1. The experiment must show that a hypothesis is either supported or not supported. 2. The results must be measurable and objective. 3. The experiment must be repeatable by other scientists.
60
What are the *outcomes* of an experimental investigation?
* Supporting evidence of scientific law. * Supporting evidence of scientific theory. ## Footnote Scientific law and theory are supported by evidence through investigations conducted through experimental design.
61
What are the steps in the **experimental design process**?
* Define variables. * Formulate a hypothesis. * Design an experiment. * Assign subjects. * Measure the dependent variable.
62
What are the **requirements** for scientific experiments?
Experiments need to be relevant to questions, hypotheses, observations, analyses, and conclusions. They must be supported by measurable, objective data and be repeatable by other scientists.
63
What is the *first step* in the experimental design process?
Defining the variables. ## Footnote The variables are factors in the experiment, including independent, dependent, and control variables.
64
What is a **hypothesis**?
An *educated guess* about the experiment outcome. ## Footnote A hypothesis is formulated before conducting the experiment and can either be supported or rejected by the experiment.
65
What are the treatment and control groups in an experiment?
* **Treatment group**: receives the item being tested. * **Control group**: does not receive changes or treatment. ## Footnote The treatment group is compared to the control group to analyze the effects of the experiment. Example: We are testing the effects of fertilizer on plants. We keep all conditions the same: sunlight, soil, type of plant, temperature; the only thing that we change is the addition of fertilizer to the treatment group.
66
How are *subjects assigned* in an experiment?
* Random selection * Random assignment ## Footnote Random selection picks a population, while random assignment assigns subjects to groups.
67
What is a **sample** in the context of research?
A portion of a population used for study.
68
What is a **variable** in a scientific experiment?
A number or feature that is changeable.
69
What is the **dependent variable** in an experiment?
The variable that changes as a result of manipulating the independent variable.
70
Where is the dependent variable usually plotted on a graph?
Y-axis ## Footnote The dependent variable is the condition that is measured to see if it changed.
71
What is the **independent variable** in an experiment?
The variable that is being changed in an experiment.
72
Where is the independent variable typically plotted on a graph?
X-axis ## Footnote The independent variable is the condition manipulated during an experiment.
73
What is a **controlled variable** in an experiment?
The facets of the experiment that are kept the same to ensure that the results are due to the independent variable alone.
74
What is the purpose of a **control** in an experiment?
To ensure only 1 variable is being tested at a time. ## Footnote A control helps validate the experimental results by providing a baseline for comparison. if multiple variables are tested at the same time a scientist will not know which variable is causing the results.
75
What is the importance of making an experiment repeatable by other scientists?
To **confirm** each other's findings.
76
What is the importance of generating measurable, objective results in an experiment?
To have results and data that can be compared. ## Footnote If there is not data to analyze, scientists will not be able to draw any conclusions about their work.
77
What is **data** in the context of experiments?
The collected measurements, observations, and calculations used to form conclusions.
78
Why is **interpreting data** important in scientific research?
To determine the meaning of the data and any implications they may have for future studies. ## Footnote Interpreting data allows researchers to bring together their findings and describe what they learned from the experiment.
79
What are the **seven general sections** of a scientific paper?
* Title * Abstract * Introduction * Materials and Methods * Results * Discussion/Conclusion * Literature Cited
80
What is the most important section of a research paper?
Results ## Footnote The results section is considered the heart of a research paper. Results should be written in an orderly and logical way so the reader can make sense of the facts.
81
What are **figures** used for in the results section?
Illustrating important trends from the experiment. ## Footnote Figures can include line graphs, bar graphs, flow charts, and other visual representations.
82
What type of figure is commonly used to compare **two variables plotted along vertical and horizontal axes?**
Line graph ## Footnote Line graphs contain three to five lines per graph.
83
What is the definition of **experimental error**?
Any variance between a measurement taken during an experiment and the established value.
84
How is experimental error calculated?
By subtracting the established, or true, value from the measured value.
85
What are the **three types of experimental error**?
* Systematic errors * Random errors * Blunders
86
What are the **two categories of errors** that are not directly attributed to human error?
1. Random error 2. Systematic error
87
Define **systematic error**.
Measurements vary significantly from the true value in a constant and predictable way. | Also known as 'Procedural Error' ## Footnote Have a detrimental effect on data because it skews the data in one direction or the other making it inaccurate. Example: Weights recorded are 5 grams heavier due to a mis-calibrated container.
88
How can systematic errors be *reduced*?
* Calibrating measuring equipment. * Assuring the anonymity and privacy of survey participants. * Using multiple measuring techniques for a single variable. * Selecting a more randomized sample to prevent sample bias.
89
Define **random error**.
Measurements differ from the true value in a random, inconsistent way. ## Footnote Measurements are fluctuating in an inconsistent manner. Numbers are "all over".
90
How can random errors be *reduced*?
* Increasing a sample size. * Taking multiple measurements of each individual and averaging those measurements. * Controlling any variables that may influence results. ## Footnote The more data you have, the less opportunity for error.
91
What is the difference between **systematic** error and **random** error in experiments?
* **Systematic error** - occurs consistently and can be caused by issues with the measuring equipment itself. * **Random error** - occurs randomly in space and time and is difficult to predict.
92
Define **blunders** in the context of experimental errors.
Errors due to the carelessness of humans. ## Footnote Example: A scientist records a weight as 85.3 pounds instead of 58.3 pounds due to tiredness.
93
Define **percent error**.
A representation of how far off measured values are from the actual values.
94
What is **drift** in the context of errors in measurements?
Gradual change in an instrument over time, affecting the accuracy of measurements.
95
Why is it important for data to be both **accurate** and **precise** in scientific research?
Good data should be both accurate and precise. ## Footnote Accurate data correctly reflects the true value, while precise data consistently produces similar results. Both are essential for reliable and valid scientific research.
96
What is the importance of evaluating scientific data?
* Influences policymaking and other important decisions. * Leads to better informed decisions and greater scientific credibility. * Can point out where a study may need to be tweaked or redesigned.
97
Why is the process of drawing conclusions considered subjective?
Because the conclusions are based on the researcher's opinions influenced by factors like background, education, and motives. ## Footnote The subjectivity of drawing conclusions highlights the importance of being unbiased in data interpretation.
98
What is the final step of any experiment?
Sharing results of the experiment.
99
What is the significance of disagreements in the scientific community about dataset interpretations?
They can lead to better science. ## Footnote Disagreements push for more information and better data for new conclusions.