Basis Of Atoms

Basis Of Atoms

1. Atoms contain Protons, Neutrons and Electrons

   • The Nucleus is the middle
     • Made of Protons and Neutrons
       • Positive Charge
       • Always the same number of Protons and Electrons
   • Electrons move around in electron shells
     • Negatively charged and no mass
   • Neutrons have no charge, so Atom has no overall charge

2. Atomic Number = Bottom Number

   • Number of Protons
     • Therefore the number of Electrons

3. Mass Number = Top Number

   • Total number of Protons AND Neutrons
     • No of Neutrons = Mass number - Atomic Number

4. Elements are atoms with the same Atomic Number

   • Protons decide what type of Atom it is
     • All of the same element have the same No. of Protons
       • Can have a different No. of Neutrons and Electrons
   • 100 different elements
   • Represented on the Periodic Table

5. Isotopes have a different number of Neutrons

   • Same Atomic No. but different Mass No.
     • Relative atomic mass is used instead
       • taking in all the masses of isotopes that make up an element
         • Relative atomic mass = Sum of (isotope abundance x isotope mass number) / sum of abundance of all the isotopes
           • Abundance means amount
             • Will be told the abundance in the Question

6. Atoms join together to make Compounds

   • Taking, giving away or sharing of electrons
     • Metals and Non-metal compounds consist of Ions
       • Non-Metals consist of Molecules
         • Covalent Bonding
       • Ionic Bonding