An electron in a hydrogen atom is excited from the ground state to the n = 4 states. Which of the following statements are true and which are false?
The n = 4 state is the first excited state.

An electron is excited from the ground state to the n = 3 state in a hydrogen atom. Which of the following statements are true? Correct any false statements. It takes more energy to ionize (remove) the electron from n = 3 than from the ground state.

An electron in a hydrogen atom is excited from the ground state to the "n=4" state. Comment on the correctness of the following statement. "n=4" is the first excited state.

To resolve an object in an electron microscope, the wavelength of the electrons must be close to the diameter of the object. What kinetic energy must the electrons have in order to resolve a protein molecule that is 2.40 nm in diameter?

In order to resolve an object in the electron microscope, the wavelength of the electrons must be close to the diameter of the object. What kinetic energy must the electrons have in order to resolve a DNA molecule, which is 2.00 nm in diameter? Take the mass of an electron to be $9.11 \times 10^{-31} \mathrm{kg}$

Why can an electron microscope resolve smaller objects than a light microscope?

Why can an electron microscope resolve smaller objects than a light microscope?

Consider a 2750-pound automobile clocked by law enforcement radar at a speed of 85.5 miles per hour. If the position of the car is known to within 5.0 feet at the time of the measurement, what is the uncertainty in the velocity of the car? Could the driver of the car reasonably evade a speeding ticket by invoking the Heisenberg uncertainty principle?

A photon has a wavelength of 624 nm. Calculate the energy of the photon in joules.

An electron in the hydrogen atom makes a transition from an energy state of principal quantum number $n_1$ to the n = 2 states. If the photon emitted has a wave length of 434 nm, what is the value of $n_1$?

The ionization energy is the energy required to completely remove an electron from the ground state of an atom or ion. Calculate the ionization energies (in KJ $mol^{-1} )$ of the $He^+$ and $Li^{2+}$ ions.

Two thin rods are made from the same material and are of lengths

$$L_1$$

and

$$L_2$$

. The two ends of the rods have the same temperature difference. What should the relation be between their diameters and lengths so that they conduct equal amounts of heat energy in a given time? (a)

$$\frac { L _ { 1 } } { L _ { 2 } } = \frac { d _ { 1 } } { d _ { 2 } }$$

, (b)

$$\frac { L _ { 1 } } { L _ { 2 } } = \frac { d _ { 2 } } { d _ { 1 } }$$

, (c)

$$\frac { L _ { 1 } } { L _ { 2 } } = \frac { d _ { 1 } ^ { 2 } } { d _ { 2 } ^ { 2 } }$$

, (d)

$$\frac { L _ { 1 } } { L _ { 2 } } = \frac { d _ { 2 } ^ { 2 } } { d _ { 1 } ^ { 2 } }$$

What are the similarities and differences between a $2 p_{x}$ and a $3 p_{y}$ hydrogen like orbital?

Discuss the similarities and differences between a 1 s and a 2 s hydrogen like orbital.