Atomic Structure

Atomic Structure

1. simplest part of an element

   • can exist on its own in a stable enviroment
   • made up of three main subatomic particles
     • protons
     • nuetrons
       • found in nucleus
     • electrons
       • found in shells around the nucleus
   • the mass is largely in the nucleus as the mass of electrons is very small compared to a proton or nuetron
   • electrically neutral
     • same amount of protons and electrons
       • protons = posotive
       • electrons = negative
     • neutrons have no charge

2. atomic number

   • number of protons in the nucleus of an atom
     • smaller number

3. mass number

   • number of protons and nuetrons in the nucleus of an atom
     • larger number

4. electron is so small it does not effect the mass number

5. an isotope is an atom with the same atomic number but different mass

   • they have the same chemical properties because they have the same amount of electrons in the outer shells

6. compounds and ions

   • a compound is a substance formed by two or more elements are chemically combined
     • e.g h20 , NaCl
   • Ions are charged particles
     • a posotive ion is called a cation
     • a negative ion is called an anion