Identify the product $(A)$ of the following reaction: $C_2H_5-O-C_2H_5 + CO \xrightarrow[500 \ atm]{BF_3 / 150^{\circ}C} A$

Which of the following is mismatched?

Which of the following is a prokaryotic kingdom?

The nature of electromagnetic waves is

$A$ nucleus at rest undergoes $\alpha-$ decay according to the equation ${}_{92}^{226}X \to Y + \alpha$. At $t = 0$,the emitted $\alpha-$ particle enters a region of space where a uniform magnetic field $\vec{B} = B_0 \hat{i}$ and an electric field $\vec{E} = E_0 \hat{i}$ exist. The $\alpha-$ particle enters the region with velocity $\vec{v} = v_0 \hat{j}$ at $x = 0$. After a time $t = \sqrt{3} \times 10^7 \frac{m_{\alpha}}{q_{\alpha} E_0}$,the particle is found to have twice its initial speed. What is the initial speed $v_0$ of the $\alpha-$ particle?

Give scientific reasons: Frogs undergo summer sleep and winter sleep (aestivation and hibernation).