Question 6
Who presented the nuclear model of the atom, and when?
The right answer is the one marked above.
Ernest Rutherford, in 1911. He proposed that at the centre of an atom is a very small region in which the mass is concentrated — the nucleus.
Niels Bohr came afterwards and took the model further, saying the electrons move in definite orbits. Mendeleev belongs to a different story altogether — he presented the first periodic table.