Answer:

Explanation:
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In this case, since Helium is undergoing a volume-pressure change, according the Boyle's law, we infer the following equation is used:

Thus, since we are not given the volume at 0.25 atm, we can solve for V2 to do so:

Thus, we plug in to obtain:

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The volume is directly proportional to the absolute temperature so the answer is A.
Answer:
The hydrogen spectrum is an important piece of evidence to show the quantized electronic structure of an atom. ... It results in the emission of electromagnetic radiation initiated by the energetically excited hydrogen atoms. The hydrogen emission spectrum comprises radiation of discrete frequencies.
The spectrum starts with red light, with a wavelength of 700 nanometers (7,000 angstroms), at the top. ... It spans the range of visible light colours, including orange and yellow and green, and ends at the bottom with blue and violet colours with a wavelength of 400 nm (4,000 angstroms).
Explanation:
Hydrogen molecules are first broken up into hydrogen atoms (hence the atomic hydrogen emission spectrum) and electrons are then promoted into higher energy levels. Suppose a particular electron is excited into the third energy level. It would tend to lose energy again by falling back down to a lower level.
The spectrum of the Sun appears as a continuous spectrum and is frequently represented as shown below. This type of spectrum is called an emission spectrum because what you are seeing is the direct radiation emitted by the source.
Answer: 1.06 kg
Explanation:
Density is defined as the mass contained per unit volume.

Given :
Density of mercury = 
volume of cylinder = volume of mercury = 
where r = radius of cylinder = 
h= height = 25.0 cm
Putting in the values we get:
volume of mercury =
(1kg=1000g)
Thus mass of mercury required to fill a hollow cylinder having an inner diameter of 2.00 cm to a height of 25.0 cm is 1.06 kg.