Part I. (8 points) Multiple-choice questions

Question 1: The red line ($\lambda = 656.28 \text{ nm}$) in the hydrogen spectrum are due to transition from a level for which $n_i > 2$ to the $n_f = 2$ level. What is the value of $n_i$?

• A. 3
• B. 4
• C. 5
• D. 6

Question 2: What orbitals do the following shapes represent?

• A. $s$ and $f$
• B. $p$ and $d$
• C. $p$ and $f$
• D. $s$ and $p$

Question 3: According to the generalised formula stated by Bohr's model, we know the energy of an electron in an hydrogen atom in the ground state is $-13.6 \text{ eV}$. What will be its energy in the second excited state?

• A. $5.6 \text{ eV}$
• B. $-1.51 \text{ eV}$
• C. $-2.35 \text{ eV}$
• D. $-3.4 \text{ eV}$

Question 4: The following diagram shows an atom at its ground state.
[↑↓] [↑↓] [↑↓] [↑↓] [ ]

• A. True
• B. False

Part II. (2 points) Long-answer question

Question 5: Write the full and shortened electron configurations of $\text{Cr}$, $\text{Cr}^{+3}$, and $\text{Cr}^{+6}$. No explanation is required.