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ATOMIC STRUCTURE - Coggle Diagram
ATOMIC STRUCTURE
Scientists and discovery
William Crookes- electrons in 1878
J.J Thomas- characteristics of cathode rays
Golstein- protons
Lord Rutherford- atomic nucleus in 1911
James Chadwick- neutron in 1932
Atom
smallest particle of an element
Element
pure substance made up of same atoms
Nucleus
centre part of an atom in which protons & neutrons are present
Orbits
electrons revolve the nucleus along the imaginary path
Postulates of Dalton's theory
matter consist of small indivisible particles-atoms
atoms cannot be created nor destroyed
Mordern atomic theory
atoms are divisible & destructible
atoms have subatomic particle: electrons, protons & neutrons
Atomic number
the number of protons in an atom
denoted by letter Z
Mass number
total no. of protons & neutrons in an atom
Noble gases
have stable electronic configuration
they do not gain or loose electrons
when there are 8 electrons in outermost shell- octet rule
Isotopes
atoms with same chemical properties but different chemical properties
Hydrogen
Protium
Dueterium
Trtinium