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:Explained Below
Explanation:
Tycho Brahe saw a super nova which inspired him to study astronomy.His observations are 5 times more accurate than other astronomers of his time and thus he was given a private island to study about astronomy .He made most accurate naked eye measurements ever.
So he can be said to be the "greatest naked eye astronomer of all time"
Answer:
<h3>0.445</h3>
Explanation:
In friction, the coefficient of friction formula is expressed as;
Ff is the frictional force = Wsinθ
R is the reaction = Wcosθ
Substitute inti the equation;
Given
θ = 24°
Hence the coefficient of kinetic friction between the box and the ramp is 0.445
Answer:
The negative electrode of a battery has an excess of positive charge
Explanation:
This is because in every battery, there is a negative electrode ( cathode ) and only positive charge is deposited on it.
For other statements:
Batteries donot store electric charge but they store chemical energy
Some batteries donot use metals for the flow of electrons, but some use hydrogen gas at a pressure of 1 atmosphere.
Answer:
Power factor = 0.87 (Approx)
Explanation:
Given:
Load = 1 Kw = 1000 watt
Current (I) = 5 A
Supply (V) = 230 V
Find:
Power factor.
Computation:
Power factor = watts / (V)(I)
Power factor = 1,000 / (230)(5)
Power factor = 1,000 / (1,150)
Power factor = 0.8695
Power factor = 0.87 (Approx)
