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

Empirical formula of compound is XF3
Compound consist of 65% F
In 100g of compound there is 65 g of F
= 65 / 19 moles of Fluorine = 3.421 moles
So moles of X = 3.421 / 3 = 1.140 moles
And in 100 g X
consist of 35 g
So the molar mass of X = 35 / 1.140 = 30.71 g = 31
approximately
And it is the mass of phosphorus
So the empirical formula for the compound is PX3
Answer:
Resistance in circuit = 0.53 ohm (Approx.)
Explanation:
Given:
Flow of current in circuit = 15 amp
Potential difference = 8 Volts
Find:
Resistance in circuit
Computation:
In an electrical system, resistance is a stopper of a material to electric current.
Resistance in circuit = Potential difference / Flow of current in circuit
Resistance in circuit = 8 / 15
Resistance in circuit = 0.53 ohm (Approx.)