Q: Which of the following numbers is correctly written in scientific notation?

$$0.00056 = 5.6 \times 10$$^{-4}$$

Question 1

Which of the following best explains why chemistry is referred to as 'the central science'?

Accepted Answer

Because chemistry connects and overlaps with many other scientific and health-related disciplines.

Question 2

Which of the following is a chemical property?

Accepted Answer

Ability to react with oxygen

Question 3

A student heats a sample of ice until it melts and then boils. Which type of change(s) has occurred?

Accepted Answer

Only physical changes

Question 4

Which of the following is a compound?

Accepted Answer

Sodium chloride (NaCl)

Question 5

Which statement about mixtures is correct?

Accepted Answer

Mixtures consist of two or more substances physically combined.

Question 6

A sample of bromine has a melting point of $$-7.2\ ^\circ\mathrm{C}$$ and a boiling point of $$58.8\ ^\circ\mathrm{C}. $$What is its physical state at $$25.0\ ^\circ\mathrm{C}$$?

Accepted Answer

Liquid

Question 7

Which of the following is the correct chemical formula for a compound containing 2 atoms of hydrogen and 1 atom of oxygen?

Accepted Answer

$$\mathrm{H}_2\mathrm{O}$$

Question 8

Which of the following is a heterogeneous mixture?

Accepted Answer

Salad dressing

Question 9

A student measures the mass of a sample as $$0.00420\ \mathrm{g}. $$How many significant figures are in this measurement?

Accepted Answer

3

Question 10

Which of the following numbers is correctly written in scientific notation?

Accepted Answer

$$0.00056 = 5.6 	imes 10$$^{-4}$$

Question 11

A patient requires an injection of $$0.012\ \mathrm{g} of a $$drug available in a $$15.0\ \mathrm{mg}/\mathrm{mL}$$ solution. How many mL should be administered?

Accepted Answer

$$0.080\ \mathrm{mL}$$

Question 12

Which equality is correct for unit conversions?

Accepted Answer

$$1\ \mathrm{in.} = 2.54\ \mathrm{cm}$$

Question 13

A rattlesnake is $$2.44\ \mathrm{m}$$ long. How many centimeters long is the snake?

Accepted Answer

$$244\ \mathrm{cm}$$

Question 14

Olive oil has a density of $$0.92\ \mathrm{g}/\mathrm{mL}. $$How many liters are in $$285\ \mathrm{g} of $$olive oil?

Accepted Answer

$$0.26\ \mathrm{L}$$

Question 15

A person with hypothermia has a temperature of $$34.8\ ^\circ\mathrm{C}. $$What is this temperature in Fahrenheit?

Accepted Answer

$$94.6\ ^\circ\mathrm{F}$$

Question 16

Which formula is used to convert Celsius to Kelvin?

Accepted Answer

$$K = ^\circ\mathrm{C} + 273.15$$

Question 17

A metal sample absorbs $$125\ \mathrm{J} of $$energy and its temperature rises from $$20.2\ ^\circ\mathrm{C} to$$ $$24.5\ ^\circ\mathrm{C}. If $$the mass is $$24.8\ \mathrm{g}$$, what is the specific heat in $$\mathrm{J}/\mathrm{g}^\circ\mathrm{C}$$?

Accepted Answer

$$1.28\ \mathrm{J}/\mathrm{g}^\circ\mathrm{C}$$

Question 18

Which of the following is an example of a physical change?

Accepted Answer

Dissolving sugar in water

Question 19

Which of the following statements about significant figures is correct?

Accepted Answer

Leading zeros are not significant.

Matter and Measurements: Foundations of Chemistry

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