Indicate whether each of the following nuclides lies within the belt of stability in Figure 21.2: (a) neon-24. For any that do not, describe a nuclear decay process that would alter the neutron-to-proton ratio in the direction of increased stability. [Section 21.2]

In the sketch below, the red spheres represent protons and the gray spheres represent neutrons. (c) Based on its atomic number and mass number, do you think the product nucleus is stable or radioactive? [Section 21.3]

The steps below show three of the steps in the radioactive decay chain for ²³²₉₀Th. The half-life of each isotope is shown below the symbol of the isotope. (a) Identify the type of radioactive decay for each of the steps (i), (ii), and (iii). [Sections 21.2 and 21.4]

The accompanying graph illustrates the decay of ⁸⁸₄₂Mo, which decays via positron emission. (a) What is the halflife of the decay? [Section 21.4]

The accompanying graph illustrates the decay of ⁸⁸₄₂Mo, which decays via positron emission. (c) What fraction of the original sample of ⁸⁸₄₂Mo remains after 12 min? [Section 21.4]

All the stable isotopes of boron, carbon, nitrogen, oxygen, and fluorine are shown in the accompanying chart (in red), along with their radioactive isotopes with t1>2 7 1 min (in blue). (b) Which radioactive isotopes are most likely to decay by beta emission? [Sections 21.2, 21.4, and 21.5]

Indicate the number of protons and neutrons in the following nuclei: (b) 193Tl.

Indicate the number of protons and neutrons in the following nuclei: (c) neptunium-237.

Give the symbol for (c) gamma radiation.

Give the symbol for (b) a beta particle.

Give the symbol for (c) a positron.

Write balanced nuclear equations for the following processes: (b) selenium-72 undergoes electron capture.

Write balanced nuclear equations for the following processes: (c) krypton-76 undergoes positron emission.

Write balanced nuclear equations for the following processes: (d) radium-226 emits alpha radiation.

Write balanced nuclear equations for the following transformations:

(b) nitrogen-13 undergoes electron capture.

Write balanced nuclear equations for the following transformations: (c) technicium-98 undergoes electron capture.

Decay of which nucleus will lead to the following products: (a) bismuth-211 by beta decay?

Decay of which nucleus will lead to the following products: (b) chromium-50 by positron emission?

Decay of which nucleus will lead to the following products: (c) tantalum-179 by electron capture?

What particle is produced during the following decay processes: (c) iodine-122 decays to xenon-122?

Predict the type of radioactive decay process for the following radionuclides: (a) ⁸₅B.

Predict the type of radioactive decay process for the following radionuclides: (b) ⁶⁸₂₉Cu.

Predict the type of radioactive decay process for the following radionuclides: (c) phosphorus-32. (d) chlorine-39.

Each of the following nuclei undergoes either beta decay or positron emission. Predict the type of emission for each: (a) tritium, 31H.

Each of the following nuclei undergoes either beta decay or positron emission. Predict the type of emission for each: b. ⁹⁹₃₈Sr

Despite the similarities in the chemical reactivity of elements in the lanthanide series, their abundances in Earth's crust vary by two orders of magnitude. This graph shows the relative abundance as a function of atomic number. Which of the following statements best explains the sawtooth variation across the series? (a) The elements with an odd atomic number lie above the belt of stability. (b) The elements with an odd atomic number lie below the belt of stability. (c) The elements with an even atomic number have a magic number of protons. (d) Pairs of protons have a special stability.