The number of spectral lines produced when an electron falls from n = 8 to n = 5 in a hydrogen atom is:

How many neutrons are present in an atom with atomic number 19 and mass number 39?

How many electrons in an atom can have the quantum numbers n = 5 and l = 2?

An atom has an electronic configuration of 1s2 2s2 2p6 3s2 3p6 3d2. What is its atomic number?

The energy of an electron in the first orbit of Li2+ is -122.4 eV. What is the ionization energy from the third orbit? (1 eV = 1.6 x 10^-19 J)

A proton and an alpha particle have the same de Broglie wavelength. What is the ratio of their velocities? (mp = 1.67 x 10^-27 kg, ma = 6.64 x 10^-27 kg)

How many possible sets of quantum numbers (n, l, m, ms) are there for electrons in the n = 3 energy level?

The wavenumber of the second line in the Paschen series of a hydrogen atom is: (RH = 1.097 x 10^7 m^-1)

What is the maximum number of orbitals in the n = 2 energy level?

An electron in a hydrogen atom is in the n = 4 state. How many possible sets of quantum numbers (n, l, ml, ms) can describe its state?

The number of spectral lines produced when an electron falls from n = 7 to n = 3 in a hydrogen atom is:

The ionization energy of a hydrogen atom is 13.6 eV. What is the ionization energy of an H ion from its ground state if its electron is in n = 2?

Which of the following particles has the smallest de Broglie wavelength if all move at the same speed?

An atom has 26 protons, 30 neutrons, and 24 electrons. What is its net charge?

A photon of wavelength 250 nm strikes a metal surface. The ejected electron has a de Broglie wavelength of 1 * 10 ^ - 9 * m What is the work function of the metal? ( , m_{e} = 9.1 * 10 ^ - 31 * kg ) c = 3 * 10 ^ 8 * m * s ^ - 1 h = 6.626 * 10 ^ - 34 * Js