Atoms, Molecules and Compounds

Atoms, Molecules and Compounds

1. atoms form bonds to make molecules or compounds

   • atoms joined up with other atoms = molecules
     • molecules containing different types of atoms = compounds

2. Atoms are always neutral

   • have electrons that is negatively charged
     • its the electrons that are involved in bond making
       • other main type of bond= covalent bond
         • atoms in bond share a pair of electrons
           • a shared pair of electrons
       • sometimes an atom loses or gains one or more electrons
         • this gives it a charge
           • charged atoms = ions
             • a positive ion & negative ion will attract and join together if they meet
               • called an ionic bond
           • negative if gains electron/s
           • positive if loses electron/s
     • move around the nucleus in layers called shells
     • electrons have a relative charge of -1.
   • Have a nucleus that is positively charged
     • contains protons and neutrons. Neutrons are neutral, protons are electrically charged
       • protons have a relative charge of +1
   • electrons aren't evenly spread
   • arrangement of electrons in the shell is often called the electronic configuration
   • The number of electrons in an atom is equal to the number of protons in its nucleus. This means atoms have no overall electrical charge.
     • when an atom gains or loses electrons it becomes a charged particle/ ion

3. Displayed and Molecular Formulas

   • Molecular Formula = CH
   • • structural=displayed

4. ATOMS LIKE TO HAVE FULL OUTER SHELLS

Images and files in the map