Atoms and Nuclei

A hydrogen atom in the ground state absorbs a photon and gets excited to the $n=2$ state. The energy of the absorbed photon is:

The ratio of the kinetic energy to the potential energy of an electron in a Bohr orbit is:

According to Bohr's model, the total energy of an electron in an atom is always negative. This indicates that:

Which transition in the hydrogen spectrum results in the emission of the $H_{\beta}$ line?

Which of the following transitions in a hydrogen atom involves the absorption of the highest energy photon?

What is the force between a nucleus of charge $Ze$ and an electron at a distance $r$ in the Bohr model?

The work done in taking an electron from the ground state to the first excited state in a hydrogen atom is:

The ratio of the area of the $n=2$ orbit to the $n=1$ orbit in a hydrogen atom is:

An alpha particle of energy $E$ is scattered through $180^{\circ}$ by a nucleus. If the energy of the alpha particle is increased to $4E$, the distance of closest approach becomes:

If an electron in a hydrogen atom rotates in an orbit of radius $r$ with velocity $v$, the equivalent current is $ev/2\pi r$. What is the ratio of these currents for $n=1$ and $n=2$?

In the study of X-ray intensity, the 'quantity' of X-rays refers to the:

The characteristic X-ray spectrum consists of:

The filament in a Coolidge tube serves as a source of:

What is the net electrical charge of an X-ray photon?

Which property of X-rays is used to detect fractures in bones?

An electron is accelerated through a potential difference of $V$. If it loses all its energy in a single collision to produce an X-ray photon, the wavelength of that photon is:

The total power of X-rays emitted from a tube is proportional to ($I$ is current, $V$ is voltage, $Z$ is atomic number):

A metal target is bombarded by $80\text{ keV}$ electrons. The $K$-shell binding energy is $69.5\text{ keV}$ and the $L$-shell binding energy is $11.5\text{ keV}$. Which of the following wavelengths will NOT be present in the spectrum?

The wavelength of the $K_{\alpha}$ line of an atom with atomic number $Z$ is $\lambda_0$. If the atom is doubly ionized (two electrons removed from the outermost shell), the new $K_{\alpha}$ wavelength $\lambda$ will be:

An X-ray tube is operating at $20\text{ kV}$. A photon is emitted with wavelength $1.0\text{ Å}$. What percentage of the electron's kinetic energy was transferred to this photon?

Which of the following is true for the isotopes of an element?

The mass number of a nucleus is always:

The nucleus is held together by which force (primarily)?

Which of the following atoms has a nucleus with the same number of neutrons as $^{14}_6C$?

If we define nuclear radius by $R = R_0 A^{1/3}$, what is the value of $R_0$ approximately in meters?

The ratio of the radii of two nuclei with mass numbers $A_1$ and $A_2$ is $1:2$. The ratio of their mass numbers $A_1:A_2$ is:

The volume of a nucleus is $V$. If the mass number is doubled, the new volume will be:

Which of the following observations about nuclear size and composition is NOT explained by the liquid drop model?

Given that the nuclear radius $R = R_0 A^{1/3}$, which of the following represents the ratio of the nuclear radius of $_{2}^{4}\text{He}$ to $_{3}^{7}\text{Li}$?

A nucleus with $Z=92$ and $A=238$ decays into a nucleus with $Z=82$ and $A=206$. How many alpha and beta minus particles are emitted?

What is the energy equivalent of a $2 \text{ kg}$ mass?

For a nucleus with mass number $A$ and atomic number $Z$, the number of neutrons $N$ is:

What is the binding energy of a nucleus that has zero mass defect?

Which of the following is equivalent to $1 \text{ Joule}$?

Binding energy per nucleon for Uranium-235 is about $7.6 \text{ MeV}$, while for its fission fragments it is about $8.5 \text{ MeV}$. The energy released per fission event is roughly:

A nucleus $A$ has a mass defect four times that of nucleus $B$. If the mass number of $A$ is twice that of $B$, the ratio of their binding energies per nucleon $(BE/A)_A : (BE/A)_B$ is:

If the binding energy of a nucleus is $E$, what is the mass defect $\Delta m$?

A stationary nucleus with mass number $A = 50$ and a binding energy per nucleon of $8.5 \text{ MeV}$ is struck by a high-energy gamma-ray photon. This results in a photodisintegration reaction that produces a nucleus with mass number $A = 48$ and two free neutrons. The binding energy per nucleon of the $A = 48$ nucleus is $8.6 \text{ MeV}$. If the two emitted neutrons have a combined kinetic energy of $4.0 \text{ MeV}$ and the $A = 48$ nucleus is assumed to be at rest, determine the energy of the incident gamma-ray photon.

Which of the following correctly describes the variation of binding energy per nucleon with mass number $A$?

The mass defect of a nucleus is $0.2 \text{ u}$. The binding energy is:

Which of the following is true for gamma radiation?

The decay constant of a radioactive sample is $0.05\text{ per year}$. Its mean life is:

Which radiation is used to sterilize medical instruments?

Radioactive nuclei are those whose $N/Z$ ratio is:

The binding energy per nucleon for a nucleus like Iron ($^{56}Fe$) is approximately:

Carbon dating is based on the decay of which isotope?

In the decay process $^{A}_{Z}X \rightarrow ^{A}_{Z+1}Y + e^- + \bar{\nu}$, the particle $\bar{\nu}$ is called:

If the distance of closest approach of an alpha particle to a nucleus is $r_0$, what will be the distance of closest approach if the kinetic energy of the alpha particle is doubled?

During a nuclear fusion process, the total mass of the products is always:

The mass of $_{8}^{16}O$ is $15.9949 \, u$. If the mass of a neutron is $1.0087 \, u$ and a proton is $1.0073 \, u$, what is the binding energy of the oxygen nucleus?

The conversion of $1$ gram of matter into energy would release approximately how much energy?

What is the primary reason why light nuclei like Hydrogen undergo fusion?

Which of the following nuclei can undergo induced fission with thermal neutrons?

Which of the following describes the nature of nuclear waste from a fission reactor?

Which of the following correctly orders the steps in a nuclear power plant's energy conversion?

What happens to the $N/Z$ ratio (Neutron to Proton ratio) of the fragments produced after the fission of a heavy nucleus like Uranium?

What is the kinetic energy of a 'thermal' neutron at room temperature ($27^\circ \text{C}$)?

The energy released in nuclear fusion is mainly due to the:

Which of the following describes the 'Fast Fission Factor' ($\epsilon$) in the four-factor formula?

If two identical nuclei of mass number $A=60$ fuse to form a single nucleus of mass number $A=120$, and the $B/A$ increases from $8.4 \text{ MeV}$ to $8.7 \text{ MeV}$, find the energy released.