1. All of the above
2. Lack of consistent sunlight
3. Nonpolluting & Can be developed anywhere
4. Protons and Neutrons
sorry the answer is so late...Hope it still helps u
:)
Also I'm pretty sure all the answers I provided are correct but I'm not sure 4 a fact so plz let me know...
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).
Answer:
The voltage across a semiconductor bar is 0.068 V.
Explanation:
Given that,
Current = 0.17 A
Electron concentration 
Electron mobility 
Length = 0.1 mm
Area = 500 μm²
We need to calculate the resistivity
Using formula of resistivity
Put the value into the formula
We need to calculate the resistance
Using formula of resistance
We need to calculate the voltage
Using formula of voltage
Put the value into the formula
Hence, The voltage across a semiconductor bar is 0.068 V.
Answer:
There will be an increase in the kinetic energy
Explanation:
A falling object converts the gravitational potential energy to the kinetic energy. The potential energy is then converted to kinetic energy followed by the conversation:
where Ep and Ek are potential and kinetic energies respectively.
This potential energy is then converted to kinetic energy. Halfway, the kinetic energy is equal to KE1.
However, the kinetic energy is given by the equation:
As the velocity increases, the kinetic energy increases. Hence KE2 will be greater than KE1
In order to persuade the electrons in the wire to flow, you need
a potential difference between the ends of the wire. Then the
electrons will want to get away from the more-negative end and
go to the more-positive end. If both ends of the wire are at the
same potential, then the electrons have no reason to go anywhere,
and they just stay where they are.
Choice-d says this.
