Scientists use a spectroscope to receive the image of a spectra of light coming from faraway stars. Spectra is sometimes considered to be the fingerprint of the elements, with each elements having different spectra.
Explanation:
They do this by examining the spectrum of light from a star. When an ingredient is inspired, it gives off the light in distinct wavelengths, or colors.
The spectra of the Sun and stars presented bright and dark lines called Fraunhofer lines. Those were shown to be generated by elements transmitting or receiving light at specific wavelengths. Because each element emits or absorbs light only at specific wavelengths, the chemical distribution of stars can be resolved.
No, the formation of dew is condensation, which is a physical change.
I believe that it is the first one: "They are quickly replenished."
Here we have to draw the mechanism of the reduction reaction between benzaldehyde and sodium borodeuteride to form the corresponding alcohol.
The reducing agent sodium borodeuteride can reduce the aldehydes to its corresponding alcohol. The reaction mechanism is shown in the attached image.
The reaction mechanism can be explained as-
The sodium borodeuteride is highly ionic in nature thus it remains as Na⁺ and BD₄⁻ The deuterium atom of BD₄⁻ attack the carbonyl carbon atom and substitute one of its deuterium as shown in the figure.
One molecule of sodium borodeuteride can reduce four molecules of benzaldehyde. The polar solvent like alcohol donates the proton as shown in the mechanism.
The converted alcohol contains the deuterium atom at the -C center. Thus benzaldehyde is converted to deuteroted benzyl alcohol.
Static electricity is the answer