The charge/mass ratio of the electron______.
Dalton’s atomic theory is successfully explained by
(i) Law of conservation of mass
(ii) Law of constant composition
(iii) Law of radioactivity
(iv) Law of multiple proportion
Dalton's atomic theory proposed that all matter was composed of atoms, indivisible and indestructible building blocks. While all atoms of an element were identical, different elements had atoms of different sizes and mass.
Dalton's atomic theory explains:
Rutherford’s scattering experiment fails for very small scattering angles because
Rutherford's scattering formula fails for very small scattering angles because due to the strong repulsive force present between the α-particles and the nucleus and also the full nuclear charge of the target atom is partially screened by its electrons.
The conclusion of Rutherford’s scattering experiment does not include
From the α scattering experiment, Rutherford concluded that:
Identify the Mg2+ ion from the following figures where, n and p represent the number of neutrons and protons respectively.
Therefore, option (d) is the correct answer.
When alpha-particles are sent through a thin metal foil, most of them go straight through the foil because_______.
When alpha particles are sent through a thin metal foil, most of them go straight through the foil because most part of the atom is empty space. In other words, there is no obstruction in the path of alpha particles.
A student weighs 30 kg. Suppose his body is entirely made up of electrons. How many electrons are there in his body?
Weight of 1 electron = 9.1 x 10-31 kg
Let 'x' electrons combine to weigh 30 kg.
∴ (9.1 x 10-31).(x) = 30
Hence, taking the value to R.H.S., we get
x = 3.29 x 1031
Rutherford’s a-particle scattering experiment showed that
(i) electrons have negative charge
(ii) the mass and positive charge of the atom is concentrated in the nucleus
(iii) neutron exists in the nucleus
(iv) most of the space in atom is empty
Which of the above statements are correct?
Points (ii) and (iv) are correct. An atom consists of a positively charged, dense and very small nucleus which have all the protons and neutrons. Positive charge is due to protons, as neutrons have no charge. Most of the space is empty because most of the alpha particles pass straight through the gold foil without any deflection.
Electrons have negative charge, it was explained by Thomson. The existance of neutron was discovered by Chadwick.
Which of the following is correct?
The ion of an atom has 2 negative charges. Mass number of the atom is 16 and the number of neutrons are 8. What is the number of electrons in the ion?
If the charge is negative, add the amount of charge to the atomic number to get the number of electrons. i.e., Here, the atomic mass given is 16, which means atomic no. should be 8
So, 8+2 = 10 is the required answer.