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

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

Q: Convert 128.5 feet to inches using the correct conversion factor.

$$ 128.5 \times 12 = 1,542 $$ inches

Q: A woman has been alive for 26.5 years. How many hours is this? (Use $$ 1 \text{ year} = 365 \text{ days} $$, $$ 1 \text{ day} = 24 \text{ hours} )$$

$$ 26.5 \times 365 \times 24 = 232,000 $$ hours

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 values that are very close to each other, but all are significantly higher than the accepted value. Which of the following best describes the 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 the following measurements: 3.5670, 10.304, and 233.1. What is the correct sum, rounded according to the rules for significant figures?

Accepted Answer

$$ 247.2 $$

Question 5

Which of the following is NOT a correct statement about significant figures?

Accepted Answer

All zeros in any number are always significant.

Question 6

A researcher wants to test the effect of temperature on the number of hours mice sleep. Which is the independent variable in this experiment?

Accepted Answer

The temperature

Question 7

Which of the following is the correct SI prefix and symbol for $$ 10$$^{-6}$$ $$?

Accepted Answer

micro-, \mu

Question 8

Convert 128.5 feet to inches using the correct conversion factor.

Accepted Answer

$$ 128.5 	imes 12 = 1,542 $$ inches

Question 9

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 10

A measurement is recorded as $$ 1.37 \pm 0.05  cm. $$What does the $$ 0.05 $$ represent?

Accepted Answer

The uncertainty of the measurement

Question 11

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 12

A woman has been alive for 26.5 years. How many hours is this? (Use $$ 1 	ext{ year} = 365 	ext{ days} $$, $$ 1 	ext{ day} = 24 	ext{ hours} )$$

Accepted Answer

$$ 26.5 	imes 365 	imes 24 = 232,000 $$ hours

Question 13

Which of the following is a correct example of a number written in scientific notation with the correct number of significant digits?

Accepted Answer

$$ 5.74 	imes 10$$^{-7}$$ $$

Question 14

Which of the following is a source of systematic error in a measurement?

Accepted Answer

Poorly calibrated instrument

Question 15

When multiplying $$ 2.9  (2 $$sig figs) by $$ 4.8 	imes 10^2$  (2 $$sig figs), what is the correct answer with the proper number of significant figures?

Accepted Answer

$$ 1.4 	imes 10^3$ $$

Question 16

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

Accepted Answer

A prediction or explanation that is testable and based on observations

Question 17

Which of the following is the correct order of the 'textbook' scientific method steps?

Accepted Answer

Observation, Research, Hypothesis, Experiment, Conclusion, Report

Question 18

Which of the following is the correct meaning and symbol for the SI prefix 'kilo-'?

Accepted Answer

1,000, symbol: k

Question 19

Which of the following is a correct statement about the propagation of uncertainty in measurements?

Accepted Answer

The uncertainty in a sum is the sum of the absolute uncertainties of the individual measurements.

Foundations of Scientific Measurement and the Scientific Method in Chemistry

Guida di studio - Domande di pratica

Study guide - Flashcard