Q: Which of the following is the correct formula for percent error?

$$ \frac{\text{Accepted} - \text{Measured}}{\text{Accepted}} \times 100 $$

Q: A student is converting $$128.5$$ feet to inches. Which conversion factor should be used?

$$\frac{12 \text{ inches}}{1 \text{ foot}}$$

Question 1

Which of the following statements best describes the difference between an observation and an inference in the scientific method?

Accepted Answer

An observation is information gathered by the senses, while an inference is an assumption based on observations and prior knowledge.

Question 2

A scientist measures the mass of a sample five times and gets the following values (in grams): 2.01, 2.00, 2.02, 2.01, 2.00. The accepted value is 2.50 g. Which of the following best describes the scientist's measurements?

Accepted Answer

The measurements are precise but not accurate.

Question 3

Which of the following is the correct formula for percent error?

Accepted Answer

$$ \frac{	ext{Accepted} - 	ext{Measured}}{	ext{Accepted}} 	imes 100 $$

Question 4

A student records a measurement as $$1.37 \pm 0.05 cm. $$What does the $$0.05$$ represent?

Accepted Answer

The uncertainty of the measurement

Question 5

Which of the following numbers has exactly three significant figures?

Accepted Answer

0.0300

Question 6

When adding $$3.5670$$, $$100.34$$, and $$233.1$$, what is the correct answer with the proper number of significant digits?

Accepted Answer

$$337.0$$

Question 7

Which of the following best describes a control group in an experiment?

Accepted Answer

The group used as a reference to compare to the experimental group.

Question 8

A researcher wants to test the effect of caffeine on memory. She gives one group of students caffeine and another group no caffeine, then tests their memory. What is the independent variable?

Accepted Answer

The amount of caffeine given

Question 9

Which of the following is the correct formula for standard deviation of a set of $$N$$ measurements $$x_i$$ with mean $$\overline{x}$$?

Accepted Answer

$$ \sigma = \sqrt{\frac{1}{N} \sum_{i=1}^{N} (x_i - \overline{x})^2$} $$

Question 10

Which of the following is a correct statement about systematic error?

Accepted Answer

It is caused by poorly calibrated instruments and affects accuracy.

Question 11

Which of the following is the correct scientific notation for the number $$0.00000574$$?

Accepted Answer

$$5.74 	imes 10$$^{-6}$$

Question 12

A woman has been alive for $$26.5$$ years. How many hours is this? (Assume $$1$$ year = $$365$$ days)

Accepted Answer

$$232,000$$ hours

Question 13

Which metric prefix represents $$10^{-6}$$?

Accepted Answer

micro-

Question 14

Which of the following is NOT a base SI unit?

Accepted Answer

Liter

Question 15

When multiplying $$4.8 by$$ $$1.6$$, both measured to two significant figures, what is the correct answer with the proper number of significant figures?

Accepted Answer

$$7.7$$

Question 16

Which of the following best describes the role of a hypothesis in the scientific method?

Accepted Answer

A hypothesis is a prediction or explanation that must be testable.

Question 17

Which of the following is the correct order of magnitude for a kilometer?

Accepted Answer

$$10^3$$

Question 18

A student is converting $$128.5$$ feet to inches. Which conversion factor should be used?

Accepted Answer

$$\frac{12 	ext{ inches}}{1 	ext{ foot}}$$

Question 19

Which of the following statements about the 'textbook' scientific method is correct?

Accepted Answer

The steps can be repeated or skipped depending on the investigation.

Foundations of Scientific Measurement and the Scientific Method in Chemistry

Guida di studio - Domande di pratica

Study guide - Flashcard