Electron
Proton
Nucleus
Helium
`12`
`6`
`10`
`14`
Rutherford's alpha-particle scattering experiment led to the discovery of electron
J J Thomson suggested that the nucleus of an atom contains protons
The atomic number of an element is the same as the number of protons in the nucleus of its atom
The mass number of an atom is equal to the number of electrons in its shells
` text()_26^59Fe`
` text()_29^61Cu`
` text()_30^61Zn`
` text()_30^60Zn^(2+)`
`Na^+ ,K^+`
`K^+,Mg^(2+)`
`Mg^(2+) , Ca^(2+)`
`Ca^(2+) , S^(2-)`
adding the number for neutrons and number of electrons
adding the number of protons and number of electrons
the number of protons only
adding the number of neutrons and number of protons
`2, 7, 8`
`2, 8, 7`
`2, 8, 8`
`7, 8, 9`
the same number of electrons as a neutral argon atom
more protons than electrons
2 unpaired electrons
20 protons
electrons
charges
nucleus
electron cloud
they have the same atomic number, but different mass numbers
they have the same number of neutrons, but different mass numbers
the sum of the number of protons and neutrons is the same, but the number of protons is different
they have the same number of neutrons, but different modes of radioactive decay
Marie Curie
Pierre Curie
Henri Becquerel
J J Thomson
very high temperature and very high pressure
low temperature and high pressure
high temperature and low pressure
very high temperature and no pressure
n = 5 to n = 3
n = 2 to n = 1
n = 3 to = 2
n = 4 to = 2
Column I | Column II | ||
---|---|---|---|
(A) | Goldstein | (1) | Atomic theory |
(B) | Chadwick | (2) | Proton |
(C) | JJ Thomson | (3) | Neutron |
(D) | John Dalton | (4) | Electron |
2, 3, 4, 1
2, 4, 3, 1
1, 4, 3, 2
1, 3, 4, 2
increasing the current in the filament
decreasing the potential difference between the cathode and the anode
decreasing the current in the filament
increasing the potential difference between the cathode and the anode
n = 2 to n = 1
n = 3 to n = 2
n = 4 to n = 3
n = 5 to n= 4
They are isomers of each other
They are isotopes of each other
They are isoelectronic with each other
All of the above
1, 2 and 3
Only 1
1 and 2
Only 2
6 protons and 6 neutrons
5 protons and 6 neutrons
6 protons, 6 neutrons and 6 electrons
12 protons, 6 neutrons and 6 electrons
Number of protons
Number of protons and electrons
Number of ions
Number of nucleons
more than the atomic number of the element
less than the atomic number of the element
more than the number of electrons in the atom
less than the number of electrons in the atom
exactly the same number of neutrons and protons
more neutrons than protons
no neutrons
no protons
Only electrons reside inside the nucleus of an atom
Both electrons and protons reside inside the nucleus of an atom
Only neutrons reside inside the nucleus of an atom
Both protons and neutrons can reside inside the nucleus of an atom
40
27
14
13
Ozone
Heavy hydrogen
Heavy water
Hydrogen peroxide
Only 1
Only 2
Both 1 and 2
Neither 1 nor 2
charge dependent
strong and highly repulsive
a central force
charge independent
Silicon
Nitrogen
Carbon
Phosphorus
Silicon
Nitrogen
Carbon
Phosphorus