Exercise 1

In the pinwheel galaxy, atomic numbers of all elements are the same as that on earth and Pauli's principle is obeyed. However, the shell closest to the nucleus is saturated with electrons before the next shell starts to fill, and the process continues this way. If each orbital can accommodate only one electron having $+\frac{1}{2}$ spin and noble gases are defined as the elements with completely filled outermost shell, which element would be the third noble gas in their periodic table:

Which of the following best describes potential energy dependence on inter atomic distance of xenon atoms where of Xenon gasis assumed as Vander wall's gas?

Which of the following statement(s) is/are true?

True statement w.r.t. the Aufbau principle is/are:

Identify the true statement(s):

The ground state energy of ${\mathrm{He}}^{+}$ion is $-54.4\mathrm{eV}$. Consider an electronic state $\psi$ of ${\mathrm{Li}}^{+2}$ whose energy, azimuthal quantum number and magnetic quantum number are $-30.6 \mathrm{eV},1$ and $0$, respectively. Which of the following statements is/are correct for the state $\psi ?$

Consider the electron in second excited state of hydrogen and assume that it has no intrinsic spin then incorrect statements in this context is/are

In a sample of $\mathrm{H}$-atoms, all the atoms are in $3^{\mathrm{rd}}$ excited state. They de-excite to the ground state in one or more transitions but no photons is observed in Paschen series. The ratio of longest and shortest wavelengths of emitted photons is $\mathrm{x}:1$. The value of '$\mathrm{x}$' is.