The graph shown below represents the variation of probability density, \( \Psi(r) \), with distance \( r \) of the electron from the nucleus. This represents:

Step 1: Analyze the graph showing the variation of probability density \( \Psi(r) \) with distance \( r \). The graph shows a single peak, followed by a monotonic decrease, and then no further peaks. This is characteristic of a 2s orbital, where the probability density function first increases, reaches a peak, and then decreases after crossing a node (zero probability at some distance from the nucleus).
Step 2: In contrast, a 1s orbital would have only a single peak and no node, while a 3s orbital would have multiple peaks and nodes. Therefore, the graph represents a 2s orbital.
The density of \(\beta\)-Fe is 7.6 g/cm\(^3\). It crystallizes in a cubic lattice with \( a = 290 \) pm.
What is the value of \( Z \)? (\( Fe = 56 \) g/mol, \( N_A = 6.022 \times 10^{23} \) mol\(^{-1}\))
Arrange the following in the increasing order of number of unpaired electrons present in the central metal ion:
I. \([MnCl_6]^{4-}\)
II. \([FeF_6]^{3-}\)
III. \([Mn(CN)_6]^{3-}\)
IV. \([Fe(CN)_6]^{3-}\)
If the roots of $\sqrt{\frac{1 - y}{y}} + \sqrt{\frac{y}{1 - y}} = \frac{5}{2}$ are $\alpha$ and $\beta$ ($\beta > \alpha$) and the equation $(\alpha + \beta)x^4 - 25\alpha \beta x^2 + (\gamma + \beta - \alpha) = 0$ has real roots, then a possible value of $y$ is: