What is the absolute mass and charge of an electron?

Fill in the blanks in the following statements:

(a) The number of protons in the nucleus of an atom is called its …………. .

(b) The total number of protons and neutrons in the nucleus of an atom is called its ………… .

(c) An atom has atomic mass number 23 and atomic number 11. The atom has ………. Electrons.

(d) An atom of an element has 11 protons, 11 electrons and 12 neutrons. The atomic mass of the atom is ………….. .

(e) If the nucleus of an atom has atomic number 17, mass number 37 abd there are 17 electrons outside the nucleus, the number of neutrons in it is …………. .

(f) Almost all the mass of an atom is concentrated in a small region of space called the ………… .

(g) Cathode rays are a beam of fast moving …………. .

(h) The anode rays obtained form hydrogen gas consist of particles called …………… .

(i) The maximum number of electrons that can be accommodated in L shell are ……………. .

(j) The maximum number of electrons that can go into the M shell is ….....

(k) The subatomic particle not present in a hydrogen atom is …………… .

(l) The electron has …………….. charge, the proton has …………….. charge, and the neutron has ……….. charge.

What is an electron? State its relative mass and charge.

Give the evidence for the existence of nucleus in an atom.

What important information is furnished about the nucleus of an atom by the alpha particle scattering experiment of Rutherford?