Atomic Structure Flashcards
Who and when was the ‘Plum Pudding Model’ made?
J.J. Thompson Plum pudding model in 1897.
Who and when was the ‘Plum Pudding Model’ disapproved?
Rutherford disapproved Plum pudding model in 1911.
Who and when discovered the neutron?
Chadwick discovered the neutron in 1932.
Properties of protons.
Relative mass = 1
Relative charge = +1
Position = nucleus
Properties of neutron.
Relative mass = 1
Relative charge = 0
Position = nucleus
Properties of electrons.
Relative mass = 1/1840
Relative charge = -1
Position = shells
What is the atomic number?
Number of protons in nucleus.
What is the atomic mass number?
Number of protons + neutrons in nucleus.
Formation of ions.
Charged particles.
Atoms lose or gain electrons.
Positive ions lose electrons.
Negative ions gain electrons.
What is the size of an atom?
Radius of 0.1 nanometers (nm) or 1x10-10^
What is the size of a nucleus?
1/10,000th size of atom.
Approx 1.0x10-14^.
What is an isotope?
Atoms of same element with same number protons but different number neutrons.
Same atomic number different mass number.
Identical reactivity of isotopes but different physical properties.
Calculation for relative atomic mass.
R.A.M = (mass no.1 x Abundance) + (mass no.2 x abundance) / total abundance
What is the relative atomic mass?
Weighted mean mass of atom compared to carbon-12 isotope, mass exactly 12.
