Calculate the nuclear binding energy of the nucleus ${ }_{11}^{23} \mathrm{Na}$. The measured atomic mass of $\frac{23}{11} \mathrm{Na}$ is $22.989767$ amu.

An example of a "pick-up" nuclear reaction is $_{2}^{3} \mathrm{He}+ _{6}^{12} \mathrm{C} \rightarrow \mathrm{X}+\alpha .$ What is the resulting nucleus?

A nucleus of 4 neutrons and 4 protons that is surrounded by 2 orbiting electrons is

(a) a positive ion.

(b) a negative ion.

(c ) an alpha particle

(d) a beta particle

Calculate the mass defect for the neon-20 nucleus. The mass of neon-20 is $19.992440 ~u$. (Hint: How many protons and neutrons does neon-20 have?)

Show that the magnetic dipole moment M of an electron orbiting the proton nucleus of a hydrogen atom is related to the orbital momentum $L$ of the electron by

$$M=\frac{e}{2 m} L.$$

Natural aluminum is all $_{13}^{27} \mathrm{Al}$. If it absorbs a neutron, what does it become? Does it decay by $\beta^{+}$ or $\beta^{-} ?$ What will be the product nucleus?

Suppose an organism usually has 24 chromosomes in its nucleus. How many chromatids would it have just after the $S$ phase of the cell cycle?

In a helium atom, which contains two electrons, do you think that on average the electrons are closer to the nucleus or farther away than in a hydrogen atom? Why?

Give the number of protons and number of neutrons in the nucleus of each of the following: (16.1) a. boron-10 b. zinc-72 c. iron- 59 d. gold-198

Describe how eukaryotic cells are able to keep such large amounts of DNA in the small volume of the cell nucleus. (Hint Review the structure of a chromosome in Chapter 10.)

At what velocity does a proton have a 6.00-fm wavelength (about the size of a nucleus)? Assume the proton is nonrelativistic. (1 femtometer =$10^{-15} \mathrm{m}).$

What is the energy of the $\alpha$ particle emitted in the decay ${ }^{2104} \mathrm{Po} \rightarrow{ }^{206} \mathrm{~Pb}+\alpha$ ? Take into account the recoil of the daughter nucleus.

Near the surface of the nucleus of a lead atom, the electric field has a strength of $3.4 \times 10^{21} \mathrm{~V} / \mathrm{m}$. What is the energy density in this field?

The two ions $K^+}and $Ca^{2+}$ each have 18 electrons surrounding the nucleus. Which would you expect to have the smaller radius? Why?