Answer:
c. Only certain energies are allowed for the electron in a hydrogen atom
Explanation:
Emission spectrum are produced when the excited electron in a atom release the energy in the form of photons to come to ground state. These photons are of different wavelengths depending on the excitation state of emitting electron or transition of electron. These electromagnetic radiation are observed through prism to produce the spectrum.
As the name indicates this spectrum is produced by emission of energy. Although the electron can be excited by different methods such as by heating but the key point is that electrons in hydrogen atom will emit the photons of same energy which they absorb and each electron can absorb only certain type of energy. So four lines were observed in the visible spectrum of hydrogen because only certain energies are observed for hydrogen atom.
Answer:
Explanation:
You need to know one piece of information for these problems. That is as follows:
There are 6.02 x 10^23 atoms in a mole of atoms or 6.02 x 10^23 molecules in a mole of molecules (actually there are 6.02 x 10^23 in a mole of anything).
So in 3.161 x 10^21 molecules of CO2 there are 3.161 molecules x (1 mole CO2/6.02 x 10^23 molecules CO2)= ?? moles CO2. Then multiply that by 2 to find the moles of O in CO2.
The others are done th same way.
Answer:
The insect exerts no force on the windshield, and the windshield strikes the insect with a large force.
Explanation:
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<span>Brass, which is made by melting copper and zinc together, is harder, stronger, morecorrosion resistant and has an attractive gold colour. It still keeps its anti-bacterial properties, which makes it a great material for door knobs, handrails and plumbing fittings. Copper has been used to make coins for centuries.</span>
Depositional landforms are the visible evidence of processes that have deposited sediments or rocks after they were transported by flowing ice or water, wind or gravity. Examples include beaches, deltas, glacial moraines, sand dunes and salt domes
