Answer:
electrons exist in specified energy levels
Explanation:
In its gold-foil scattering with alpha particles, Rutherford proved that the plum-pudding model of the atom theorised by Thomson was wrong.
From his experiment, Rutherford inferred that the atom actually consists of a very small nucleus, where all the positive charge is concentrated, and the rest of the atom is basically empty, with the electrons (negatively charged) orbiting around the nucleus at very large distance.
However, Rutherford did not specify anything about the orbits of the electrons. Later, Bohr predicted that the electrons actually orbit the nucleus in specific orbits, each orbit corresponding to a specific energy level. Bohr's model found confirmation in the observation of the emission spectrum lines: when an electron in one of the higher energy level jumps down into an orbit with lower energy, the atom emits a photon which has an energy exactly equal to the difference in energy between the two orbits (and this energy of the photon corresponds to a precise wavelength).
Asteroid belt :-) hope it helped
Time = (distance covered) / (speed)
Time = (224 mi) / (56 mi/hr)
<em>Time = 4 hours</em>
A substance with LOW pH. The lower the pH, the higher the acidity level is. pH has a direct effect on how acidic a substance is. For an example, battery acid. Battery acid has a pH level of about 1. This means that battery acid is very acidic. A substance is concidered acidic when it dips below the neutral pH level of 7.
The substance is DNA and it would be found in the nucleus.
