The illustration in figure below shows a uniform metre rule weighing 30 N pivoted on a wedge placed under the 40 cm mark and car
rying a weight of 70 N hanging 2 from the 10 cm mark. The ruler is balanced horizontally by a weight W hanging from the 100 cm mark. Calculate the value of the weight W.
1 answer:
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Answer:
B) Within an atom, an electron can have only particular energies.
Explanation:
As we know that electrons have energy but apart from electrons we know that protons and neutrons inside the nucleus of atom will also have energy in them.
rest all the statements are true as we have
A) Electrons orbit the nucleus rather like planets orbiting the Sun.
TRUE, because electrons can move in stationary orbit around the nucleus
C) Electrons can jump between energy levels in an atom only if they receive or give up an amount of energy equal to the difference in energy between the energy levels.
Difference amount of energy is lost or absorbed by the electron in form of photons
D) An electron has a negative electrical charge.
Charge of an electron is given as
E) Electrons have very little mass compared to protons or neutrons
Mass of an electron is given as
mass of proton or neutron