Answer:
- Option <em>A), Planck.</em>
Explanation:
The first scientist to propose that an object could emit only certain amounts of energy was <em>Max Planck</em>.
Incandescent (very hot) objects emit different color of lights, i.e. different wavelengths, but by 1900 it was believed that the light (energy) was emitted in a continuous way.
Since the wave model did not explain the emission of such specific wavelengths, when the German physicist <em>Max Planck</em> (1858 - 1947) studied the light emitted by incandescent objects, he proposed that the objects (the matter) could gain or lose energy only in small specific amounts or packages of energy called quanta (plural of quantum).
Planck, later, established the mathematical relation between the energy of a quantum of light with the frequency of such the radiation (light emitted). This is the formula:
Where, E is the energy, h is Planck's constant, and ν is the frequency.
Answer:
Pure solid and liquid compounds possess sharp melting and boiling points.
Explanation:
Therefore, melting and boiling points of a compound can be used as a criteria of purity. ... Sometimes during cooling minute quantity of the substance (solid which is being purified) is added to the solution to facilitate the initial crystallisation.
Answer:
A
Explanation:
The lower mantle is under the surface of the earth while the ocieanic crust is above the surface
?? Is that the whole question?
I think so. You should check the Periodic Table. ;-)
