The ascending limb of the Loop of Henle is permeable to which of the following?

$A$ semiconductor $X$ is made by doping a germanium crystal with arsenic $(Z = 33)$. $A$ second semiconductor $Y$ is made by doping germanium with indium $(Z = 49)$. The two are joined end to end and connected to a battery as shown. Which of the following statements is correct?

Write the resonance structures for $SO_{3}$,$NO_{2}$,and $NO_{3}^{-}$.

$A$ nucleus of uranium decays at rest into nuclei of thorium and helium. Then:

The chemical formula of 'tear gas' is

Two identical photo-cathodes receive light of frequencies $f_1$ and $f_2$. If the velocities of the photoelectrons (of mass $m$) coming out are respectively $v_1$ and $v_2$,then: