Q: A student wants to convert $$25.0\ \text{cm} to $$meters. Which conversion factor should they use?

$$1\ \text{m} = 100\ \text{cm}$$

Question 1

Which statement best explains why graphite and diamond, though both made of carbon, have different properties?

Accepted Answer

Their properties are determined by the arrangement and connection of carbon atoms.

Question 2

A student measures the mass of a sample as 12.30 g and its volume as 4.1 cm$$^3. $$What is the density of the sample, reported with the correct number of significant figures?

Accepted Answer

$$3.0\ 	ext{g/cm}^3$$

Question 3

Which of the following is a chemical property?

Accepted Answer

The flammability of gasoline

Question 4

A scientist observes that the mass of reactants in a chemical reaction equals the mass of products. Which scientific concept does this observation support?

Accepted Answer

Law of conservation of mass

Question 5

Which of the following is NOT considered matter?

Accepted Answer

Light

Question 6

A sample of steel has a mass of 157 g and a density of $$7.85\ 	ext{g/cm}^3. $$What is its volume?

Accepted Answer

$$20.0\ 	ext{cm}^3$$

Question 7

Which of the following best describes a scientific theory?

Accepted Answer

A well-supported explanation for why a phenomenon occurs, capable of predicting new results.

Question 8

Convert $$0.00045 to $$scientific notation.

Accepted Answer

$$4.5 	imes 10$$^{-4}$$

Question 9

Which statement about the periodic table is correct?

Accepted Answer

Elements are arranged in order of increasing atomic number.

Question 10

Which element is a metalloid?

Accepted Answer

Silicon

Question 11

A student wants to convert $$25.0\ 	ext{cm} to $$meters. Which conversion factor should they use?

Accepted Answer

$$1\ 	ext{m} = 100\ 	ext{cm}$$

Question 12

Which of the following is a heterogeneous mixture?

Accepted Answer

Oil and water

Question 13

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes have the same number of protons but different numbers of neutrons.

Question 14

Which of the following is a physical change?

Accepted Answer

Melting ice

Question 15

Which equation correctly expresses the relationship between mass, volume, and density?

Accepted Answer

$$D = \frac{m}{v}$$

Question 16

Which of the following is the SI unit for energy?

Accepted Answer

Joule

Question 17

A chemical reaction absorbs energy from its surroundings. What type of reaction is this?

Accepted Answer

Endothermic

Question 18

Which of the following best describes a cation?

Accepted Answer

An ion with a positive charge

Question 19

Which of the following is true about main group elements and their ions?

Accepted Answer

They tend to gain or lose electrons to achieve the same number of valence electrons as the nearest noble gas.

Question 20

A sample contains 70% isotope A (mass = 10 amu) and 30% isotope B (mass = 12 amu). What is the average atomic mass?

Accepted Answer

$$10.6\ 	ext{amu}$$

Introduction to Chemistry: Foundations, Measurement, Matter, and Atomic Theory

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