From cathode ray experiments, J. J. Thomson estimated that the mass of an electron was “about a thousandth” of the mass of a proton. How accurate is that estimate? Calculate the ratio of the mass of an electron to the mass of a proton.

Indicate whether the following peaks in the mass spectrum of 1-heptanol are odd-electron or even-electron ions. (Don't attempt to give their structures.) (a) $m / 2=83$ (b) $m / z=56$ (c) $m / 2=41$

A photon with wavelength $\lambda=0.0900 \mathrm{~nm}$ is incident on an electron that is initially at rest. If the photon scatters in the backward direction, what is the magnitude of the linear momentum of the electron just after the collision with the photon?

An electron is confined to a box of width 0.25 nm. (a) Draw an energy-level diagram representing the first five states of the electron. (b) Calculate the wavelengths of the emitted photons when the electron makes transitions between the fourth and the second excited states, between the second excited state and the ground state, and between the third and the second excited states.

(a) An electron moves counterclockwise around a nucleus in a horizontal plane. Assuming that it behaves as a classical particle, what is the direction of the magnetic field produced by the electron? (b) The same one-electron atom is placed in an external magnetic field whose $\vec{B}$ field points horizontally from right to left. Draw a picture showing what happens to the atom.

The mass of a proton is about $1.67 \times 10^{-27}$ kilogram. The mass of an electron is about $9.11 \times 10^{-31}$ kilogram. About how many times as massive as an electron is a proton?

An electron with kinetic energy $K$ moving horizontally to the right in a tube of length $L$ passes through a uniform electric field with an $\vec{E}$ field that points downward. The electron is initially moving toward the center of the screen. Develop an expression for the strength of the field so the electron hits the screen a vertical height $h$ above the center.

(a) Find the frequency of revolution of an electron with an energy of 189 eV in a uniform magnetic field of magnitude

$$70.0 \mu T$$

. (b) Calculate the radius of the path of this electron if its velocity is perpendicular to the magnetic field.

Write a Lewis structure for the following simple molecules. Show all bonding valence electron pairs as lines and all nonbonding valence electron pairs as dots.

d. $\mathrm{SiCl}_4$

Write a Lewis structure for the following simple molecules. Show all bonding valence electron pairs as lines and all nonbonding valence electron pairs as dots.

c. $\mathrm{CF}_4$

The ground-state wave function for the electron in a hydrogen atom is

$$\psi _ { 1 s } ( r ) = \frac { 1 } { \sqrt { \pi a _ { 0 } ^ { 3 } } } e ^ { - r / a _ { 0 } }$$

where r is the radial coordinate of the electron and $a_0$ is the Bohr radius.

Find the probability of locating the electron between $r_1 = a_0/2$ and $r_2 = 3a_0/2$.

Potassium cyanide is a potent poison that kills by inhibiting electron transport when $\mathrm{CN}^{-}$binds to the $\mathrm{Fe}^{3+}$ in the cytochrome heme groups. Why would this stop electron transport?

Assume that the beam energy of an electron-positron collider is approximately $4.73 \mathrm{GeV}$. What is the total mass $(W)$ of a particle produced in the annihilation of an electron and positron in this collider? What meson might be produced?

We cannot exactly specify the location of an electron in an atom; we can discuss only where an electron is most likely to be at any given time. How does the concept of an orbital show this?