Answer:
He developed the concept of concentric electron energy levels
Explanation:
Before Bohr's model, Rutherford's model was proposed. This model explains most of the properties of the atom but failed to explain the stability of the atom.
As per Rutherford's model, electrons revolve around the nucleus in the orbit.
But revolving electron in their orbit around nucleus would give up energy and so gradually move towards the nucleus and therefore, eventually collapse.
Bohr's proposed that the electrons around the nucleus move orbit of fixed energy called "stationary states". Electrons in these stationary states do not radiate energy.
Therefore, proposal of concentric electron energy levels refine the atomic models.
PH = -log([H+])
[H+] = 10^(-pH)
[H+] = 10^(-9)
[H+][OH-] = Kw
Kw = 1.0*10^-14 at 25 degrees celsius.
[OH-] = Kw/[H+] = (1.0*10^-14)/(1*10^-9) = 1.0*10^-5
The concentration of OH- ions is 1.0*10^-5 M.
Helium is a chemical element of the atomic number 2, an inert gas that is the lightest member of the noble gas series.
These means, Helium is lighter than air, and for this is why all other balloons may not float.
The helium balloon displaces an amount of air (Just like an empty water bottle displaces an amount of water). As long as the weight of the helium plus the balloon fabric is lighter than the air displaces, the balloon will float in the air.
Answer:
Diamond can indeed be set on fire since it is made of carbon. ... You can even burn diamond in a regular flame if you are patient and conditions are right. To accelerate the burning of diamond, you can give it more heat and more oxygen.
Explanation:
Answer:
See explanation
Explanation:
The mechanism for the formation of bromohexane from hexene has been clearly shown in the image attached to this answer.
Hexene is attacked by HBr and a carbocation is first formed as shown. The carbocation is flat and planar. it can be attacked on either face by the bromide ion.
Attack on either faces yields a racemic mixture of the R and S enantiomer as shown in the image.
You can use the mechanism shown to fill in the structures.
