10.4 Nuclear reactions  (Page 5/19)

What is the key difference and the key similarity between beta ( ${\beta }^{-}$ ) decay and alpha decay?

What is the difference between $\gamma$ rays and characteristic X-rays and visible light?

What characteristics of radioactivity show it to be nuclear in origin and not atomic?

Consider [link] . If the magnetic field is replaced by an electric field pointed in toward the page, in which directions will the $\alpha$ -, ${\beta }^{+}$ -, and $\gamma$ rays bend?

Why is Earth’s core molten?

${}^{249}\text{C}\text{f}$ undergoes alpha decay. (a) Write the reaction equation. (b) Find the energy released in the decay.

(a) Calculate the energy released in the $\alpha$ decay of ${}^{238}\text{U}$ . (b) What fraction of the mass of a single ${}^{238}\text{U}$ is destroyed in the decay? The mass of ${}^{234}\text{T}\text{h}$ is 234.043593 u. (c) Although the fractional mass loss is large for a single nucleus, it is difficult to observe for an entire macroscopic sample of uranium. Why is this?

The ${\beta }^{-}$ particles emitted in the decay of ${}^3\text{H}$ (tritium) interact with matter to create light in a glow-in-the-dark exit sign. At the time of manufacture, such a sign contains 15.0 Ci of ${}^3\text{H}$ . (a) What is the mass of the tritium? (b) What is its activity 5.00 y after manufacture?

(a) Write the complete ${\beta }^{-}$ decay equation for ${}^{90}\text{S}\text{r},$ a major waste product of nuclear reactors. (b) Find the energy released in the decay.

Write a nuclear ${\beta }^{-}$ decay reaction that produces the ${}^{90}\text{Y}$ nucleus. ( Hint: The parent nuclide is a major waste product of reactors and has chemistry similar to calcium, so that it is concentrated in bones if ingested.)

Write the complete decay equation in the complete ${}_Z^A\text{X}{}_N$ notation for the beta ( ${\beta }^{-}$ ) decay of ${}^3\text{H}$ (tritium), a manufactured isotope of hydrogen used in some digital watch displays, and manufactured primarily for use in hydrogen bombs.

If a 1.50-cm-thick piece of lead can absorb $90.0\text{\%}$ of the rays from a radioactive source, how many centimeters of lead are needed to absorb all but $0.100\text{\%}$ of the rays?

An electron can interact with a nucleus through the beta-decay process:

${}_Z^A\text{X}\text{+}{e}^{-}\to Y+v_e$ .

(a) Write the complete reaction equation for electron capture by ${}^7\text{Be}$ .

(b) Calculate the energy released.

(a) Write the complete reaction equation for electron capture by ${}^{15}\text{O}.$

(b) Calculate the energy released.

A rare decay mode has been observed in which ${}^{222}\text{R}\text{a}$ emits a ${}^{14}\text{C}$ nucleus. (a) The decay equation is ${}^{222}\text{Ra}\to {}^A\text{X}+{}^{14}\text{C}$ . Identify the nuclide ${}^A\text{X}$ . (b) Find the energy emitted in the decay. The mass of ${}^{222}\text{Ra}$ is 222.015353 u.