Chapter 10

Write the symbol for the isotope described. a. 12 protons, 12 electrons, 13 neutrons b. 17 protons, 17 electrons, 20 neutrons c. 53 protons, 53 electrons, 78 neutrons d. 92 protons, 92 electrons, 146 neutrons

Fill in the missing numbers in each equation. a. \({ }^{196} \mathrm{~Pb}+{ }_{-1}^{0} \mathrm{e} \rightarrow=\mathrm{Tl}\) b. \({ }_{15}^{28} \mathrm{P} \rightarrow=\mathrm{Si}+{ }_{1}^{0} \mathrm{e}\) c. \({ }_{88}^{226} \mathrm{Ra} \rightarrow=\mathrm{Rn}+{ }_{2}^{4} \alpha\) d. \({ }_{30}^{73} \mathrm{Zn} \rightarrow=\mathrm{Ga}+{ }_{-1}^{0} \mathrm{e}\)

Write balanced nuclear reactions for each of the following. a. Francium- 220 undergoes alpha decay. b. Arsenic-76 undergoes beta decay. c. Uranium- 231 captures an electron. d. Promethium-143 emits a positron.

Describe the main difference between fission and fusion.

What percent of a sample remains after one half-life? Three half-lives?

The half-life of polonium- 218 is \(3.0 \mathrm{~min}\). How much of a \(0.540 \mathrm{mg}\) sample would remain after \(9.0\) minutes have passed?

The half-life of hydrogen-3, commonly known as tritium, is \(12.26\) years. If \(4.48 \mathrm{mg}\) of tritium has decayed to \(0.280 \mathrm{mg}\), how much time has passed?

The half-life of protactinium- 234 is \(6.69\) hours. If a \(0.812 \mathrm{mg}\) sample of Pa- 239 decays for \(40.14\) hours, what mass of the isotope remains?

\(2.86 \mathrm{~g}\) of a certain radioisotope decays to \(0.358 \mathrm{~g}\) over a period of \(22.8\) minutes. What is the half-life of the radioisotope?

A radioisotope decays from \(55.9 \mathrm{~g}\) to \(6.99 \mathrm{~g}\) over a period of \(72.5\) hours. What is the half-life of the isotope?

A sample of a radioisotope with a half-life of \(9.0\) hours has an activity of \(25.4 \mathrm{mCi}\) after 36 hours. What was the original activity of the sample?

What volume of a radioisotope should be given if a patient needs \(125 \mathrm{mCi}\) of a solution which contains \(45 \mathrm{mCi}\) in \(5.0 \mathrm{~mL}\) ?

Sodium- 24 is used to treat leukemia. A \(36-\mathrm{kg}\) patient is prescribed \(145 \mu \mathrm{Ci} / \mathrm{kg}\) and it is supplied to the hospital in a vial containing \(250 \mu \mathrm{Ci} / \mathrm{mL}\). What volume should be given to the patient?

Lead-212 is one of the radioisotopes used in the treatment of breast cancer. A patient needs a \(15 \mu \mathrm{Ci}\) dose and it is supplied as a solution with a concentration of \(2.5 \mu \mathrm{Ci} / \mathrm{mL}\). What volume does the patient need? Given the half-life of lead is \(10.6\) hours, what will be the radioactivity of the sample after approximately four days?

Identify each of the following as a physical or chemical change. a. melting ice b. boiling water c. cooking eggs d. dissolving salt in water e. burning match f. metal reacting with \(\mathrm{HCl}\) g. mixing \(\mathrm{NaCl}\) and \(\mathrm{KCl}\) h. decomposition of hydrogen peroxide

Give two signs that indicate a chemical change is occurring.

How many atoms of each element are represented by the following combinations of coefficients and chemical formulas? a. \(5 \mathrm{Br}_{2}\) b. \(2 \mathrm{NH}_{3}\) c. \(4\left(\mathrm{NH}_{4}\right)_{2} \mathrm{SO}_{4}\) d. \(2 \mathrm{CH}_{3} \mathrm{COOH}\) e. \(3 \mathrm{Fe}\left(\mathrm{NO}_{3}\right)_{3}\) f. \(2 \mathrm{~K}_{3} \mathrm{PO}_{4}\)

Balance the following equations. a. \(\mathrm{Zn}(s)+\mathrm{HCl}(a q) \rightarrow \mathrm{ZnCl}_{2}(a q)+\mathrm{H}_{2}(g)\) b. \(\mathrm{Li}(s)+\mathrm{N}_{2}(g) \rightarrow \mathrm{Li}_{3} \mathrm{~N}(s)\) c. \(\mathrm{Ca}(\mathrm{OH})_{2}+\mathrm{HBr} \rightarrow \mathrm{CaBr}_{2}+\mathrm{H}_{2} \mathrm{O}\) d. \(\mathrm{C}_{4} \mathrm{H}_{10}+\mathrm{O}_{2} \rightarrow \mathrm{CO}_{2}+\mathrm{H}_{2} \mathrm{O}\) e. \(\mathrm{NH}_{3}+\mathrm{CuO} \rightarrow \mathrm{Cu}+\mathrm{N}_{2}+\mathrm{H}_{2} \mathrm{O}\)

Balance the following equations. a. \(\mathrm{Fe}(\mathrm{s})+\mathrm{Cl}_{2}(g) \rightarrow \mathrm{FeCl}_{3}(g)\) b. \(\mathrm{C}_{4} \mathrm{H}_{10} \mathrm{O}+\mathrm{O}_{2} \rightarrow \mathrm{CO}_{2}+\mathrm{H}_{2} \mathrm{O}\) C. \(\mathrm{As}+\mathrm{NaOH} \rightarrow \mathrm{Na}_{3} \mathrm{AsO}_{3}+\mathrm{H}_{2}\) d. \(\mathrm{SiO}_{2}+\mathrm{HF} \rightarrow \mathrm{SiF}_{4}+\mathrm{H}_{2} \mathrm{O}\) e. \(\mathrm{N}_{2}+\mathrm{O}_{2}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{HNO}_{3}\)