Chapter 1

Explain this statement in your own words and give an example. The properties of the substances around us depend on the atoms and molecules that compose them.

Describe the scientific approach to knowledge. How does it differ from other approaches?

Explain the differences between a hypothesis, a law, and a theory.

What theory did John Dalton formulate?

What are two different ways to classify matter?

How do solids, liquids, and gases differ?

What is the difference between a crystalline solid and an amorphous solid?

Explain the difference between a pure substance and a mixture.

Explain the difference between an element and a compound.

Explain the difference between a homogeneous and a heterogeneous mixture

What kind of mixtures can be separated by filtration?

Explain how distillation is used to separate mixtures.

What is the difference between a physical property and a chemical property?

What is the difference between a physical change and a chemical change? List some examples of each.

Explain the significance of the law of conservation of energy.

What kind of energy is chemical energy? In what way is an elevated weight similar to a tank of gasoline?

What are the standard SI base units of length, mass, time, and temperature?

What are the three common temperature scales? Does the size of a degree differ among them?

What are prefix multipliers? List some examples.

What is a derived unit? List an example.

Explain the difference between density and mass.

Explain the difference between intensive and extensive properties.

What is the meaning of the number of digits reported in a measured quantity?

When multiplying or dividing measured quantities, what determines the number of significant figures in the result?

When adding or subtracting measured quantities, what determines the number of significant figures in the result?

Explain the difference between precision and accuracy.

Explain the difference between random error and systematic error.

Classify each statement as an observation, a law, or a theory. MISSED THIS? Read Section 1.2 a. All matter is made of tiny, indestructible particles called atoms. b. When iron rusts in a closed container, the mass of the container and its contents does not change. c. In chemical reactions, matter is neither created nor destroyed. d. When a match burns, heat is released.

Classify each statement as an observation, a law, or a theory. a. Chlorine is a highly reactive gas. b. If elements are listed in order of increasing mass of their atoms, their chemical reactivities follow a repeating pattern. c. Neon is an inert (or nonreactive) gas. d. The reactivity of elements depends on the arrangement of their electrons.

A chemist decomposes several samples of carbon monoxide into carbon and oxygen and weighs the resultant elements. The results are shown in the table. MISSED THIS? Read Section 1.2 $$\begin{array}{ccc}\text { Sample } & \text { Mass of Carbon (g) } & \text { Mass of Oxygen (g) } \\\\\hline 1 & 6 & 8 \\ \hline 2 & 12 & 16 \\\\\hline 3 & 18 & 24 \\\\\hline\end{array}$$ a. Do you notice a pattern in these results? Next, the chemist decomposes several samples of hydrogen peroxide into hydrogen and oxygen. The results are shown in the table. $$\begin{array}{ccc}\text { Sample } & \text { Mass of Hydrogen (g) } & \text { Mass of Oxygen (g) } \\\\\hline 1 & 0.5 & 8 \\\\\hline 2 & 1 & 16 \\\\\hline 3 & 1.5 & 24 \\\\\hline\end{array}$$ b. Do you notice a similarity between these results and those for carbon monoxide in part a? c. Can you formulate a law from your observations in a and b? d. Can you formulate a hypothesis that might explain your law in c?

When astronomers observe distant galaxies, they can tell that most of them are moving away from one another. In addition, the more distant the galaxies, the more rapidly they are likely to be moving away from each other. Can you devise a hypothesis to explain these observations?

Classify each substance as a pure substance or a mixture. If it is a pure substance, classify it as an element or a compound. If it is a mixture, classify it as homogeneous or heterogeneous. a. wine b. beef stew c. iron d. carbon monoxide

Classify each of the listed properties of isopropyl alcohol (also known as rubbing alcohol) as physical or chemical. MISSED THIS? Read Section 1.4 a. colorless b. flammable c. liquid at room temperature d. density \(=0.79 \mathrm{~g} / \mathrm{mL}\) e. mixes with water

Classify each of the listed properties of ozone (a pollutant in the lower atmosphere but part of a protective shield against UV light in the upper atmosphere) as physical or chemical. a. bluish color b. pungent odor c. very reactive d. decomposes on exposure to ultraviolet light e. gas at room temperature

Classify each property as physical or chemical. a. the boiling point of ethyl alcohol b. the temperature at which dry ice evaporates c. the tendency of iron to rust d. the color of gold

Classify each change as physical or chemical. MISSED THIS? Read Section 1.4 a. Natural gas burns in a stove. b. The liquid propane in a gas grill evaporates because the valve was left open. c. The liquid propane in a gas grill burns in a flame. d. A bicycle frame rusts on repeated exposure to air and water.

Classify each change as physical or chemical. a. Sugar burns when heated in a skillet. b. Sugar dissolves in water. c. A platinum ring becomes dull because of continued abrasion. d. A silver surface becomes tarnished after exposure to air for a long period of time.

Convert each temperature. MISSED THIS? Read Section 1.6; Watch \(\mathrm{KCV} 1.6\) a. \(32^{\circ} \mathrm{F}\) to \({ }^{\circ} \mathrm{C}\) (temperature at which water freezes) b. \(77 \mathrm{~K}\) to \({ }^{\circ} \mathrm{F}\) (temperature of liquid nitrogen) c. \(-109^{\circ} \mathrm{F}\) to \({ }^{\circ} \mathrm{C}\) (temperature of dry ice) d. \(98.6^{\circ} \mathrm{F}\) to \(\mathrm{K}\) (body temperature)

Convert each temperature. a. \(212^{\circ} \mathrm{F}\) to \({ }^{\circ} \mathrm{C}\) (temperature of boiling water at sea level) b. \(22^{\circ} \mathrm{C}\) to \(\mathrm{K}\) (approximate room temperature) c. \(0.00 \mathrm{~K}\) to \({ }^{\circ} \mathrm{F}\) (coldest temperature possible, also known as absolute zero) d. \(2.735 \mathrm{~K}\) to \({ }^{\circ} \mathrm{C}\) (average temperature of the universe as measured from background black body radiation)

The coldest ground-level temperature ever measured on Earth is \(-128.6^{\circ} \mathrm{F},\) recorded on July \(21,1983,\) in Antarctica. Convert that temperature to \({ }^{\circ} \mathrm{C}\) and \(\mathrm{K}\). MISSED THIS? Read Section 1.6; Watch \(\mathrm{KCV} 1.6\).

The warmest temperature ever measured in the United States is \(134^{\circ} \mathrm{F},\) recorded on July \(10,1913,\) in Death Valley, California. Convert that temperature to \({ }^{\circ} \mathrm{C}\) and \(\mathrm{K}\).

Use the prefix multipliers to express each measurement without exponents. MISSED THIS? Read Section 1.6; Watch \(\mathrm{KCV} 1.6\) a. \(1.2 \times 10^{-9} \mathrm{~m}\) b. \(22 \times 10^{-15} \mathrm{~s}\) c. \(1.5 \times 10^{9} \mathrm{~g}\) d. \(3.5 \times 10^{6} \mathrm{~L}\)

Use prefix multipliers to express each measurement without exponents. a. \(38.8 \times 10^{5} \mathrm{~g}\) b. \(55.2 \times 10^{-10} \mathrm{~s}\) c. \(23.4 \times 10^{11} \mathrm{~m}\) d. \(87.9 \times 10^{-7} \mathrm{~L}\)

Use scientific notation to express each quantity with only base units (no prefix multipliers). MISSED THIS? Read Section 1.6; Watch KCV 1.6 a. \(4.5 \mathrm{~ns}\) b. 18 fs c. \(128 \mathrm{pm}\) d. \(35 \mu \mathrm{m}\)

Use scientific notation to express each quantity with only base units (no prefix multipliers). a. \(35 \mu \mathrm{L}\) b. \(225 \mathrm{Mm}\) c. \(133 \mathrm{Tg}\) d. \(1.5 \mathrm{cg}\)

Complete the table. a. \(355 \mathrm{~km} / \mathrm{s}\) _____cm/s _____s/ms b. \(1228 \mathrm{~g} / \mathrm{L}\) _____g/mL ______ kg/mL c. \(554 \mathrm{mK} / \mathrm{s}\) _____K/s _____ \(\mu \mathrm{K} / \mathrm{ms}\) d. \(2.554 \mathrm{mg} / \mathrm{mL}\) _____g/L _____\(\mu \mathrm{g} / \mathrm{mL}\)

Express the quantity \(254,998 \mathrm{~m}\) in each unit. MISSED THIS? Read Section 1.6; Watch KCV 1.6 a. \(\mathrm{km}\) b. \(\mathrm{Mm}\) c. \(\mathrm{mm}\) d. \(\mathrm{cm}\)

Express the quantity \(556.2 \times 10^{-12} \mathrm{~s}\) in each unit. a. ms b. ns c. ps d. fs

How many \(1-\mathrm{cm}\) squares would it take to construct a square that is \(1 \mathrm{~m}\) on each side? MISSED THIS? Read Section 1.6

How many \(1-\mathrm{cm}\) cubes would it take to construct a cube that is \(4 \mathrm{~cm}\) on edge?