Which of the following statements about the atom is/are correct?
I. Energy is needed to remove electrons from an atom
II. Particles in the nucleus of an atom are bound together by strong forces.
III. A large amount of energy is required to separate the particles in the nucleus of an atom.
IV. When the nucleus of a uranium atom is split, the energy released accounts for the difference in the masses of the products and the parent nucleus
I only
I and II only
I and III only
II and IV only
I, II, III and IV
Correct answer is D
No explanation has been provided for this answer.
When the pressure of the gas in a discharge tube is gradually lowered.
I. there is a violet glow in the tube
II. the glow in the tube splits into bands which get further apart.
III, the glow and the bands eventually disappear and there is a green fluorescence in the tube. IV. the tube breaks into pieces.
Which of the following are correct?
I and II only
I and III only
I and IV only
I, II and III only
I, II III and IV
Correct answer is B
No explanation has been provided for this answer.
Which of the following particles conduct electricity through salty water?
Atom
molecules
Electrons
Neutrons
Ions
Correct answer is E
No explanation has been provided for this answer.
I. The capacitor in the circuit
II. The make and break contact in the circuit
III. The ratio of turns in the secondary to that in the primary
l only
II only
I and II only
II and III only
I, II and III
Correct answer is C
No explanation has been provided for this answer.