1. Elements can be classified according to their properties and electronic structure into: 1- Metals 2- Nonmetals 3- Nobel gases

3. Atoms of metals tend to give (grant) their outermost electrons to other atoms and change into (positive ions) which carry a number of positive charge equal to the number of the given electron (s).

4. It is the atom which loses an electron or more during the chemical reactions. 282 Mg Lose 2 electrons 24 12 Mg +2 2 8

5. They are the elements which have more than (4) electrons in the outer most energy level Properties of nonmetals 1.They are solids and gases except Bromine (Br) which is the only liquid non metallic element 2.They have no luster 3.They are bad conductor of heat and electricity except (graphite carbon) which is a good conductor to electricity 4.They are not malleable or ductile

6. Atoms of Non metals tend to gain electrons from other atoms to complete their outermost energy level and Change into (NEGATIVE IONS) which carry a number of Negative charges equal to the number of the gained electrons..

7. It is the atom which gain an electron or more during the chemical reaction.

8. They are elements in which the outer most electron Shells are completely filled with electrons so they don’t Participate in any chemical combination in ordinary conditions.

9. We will study two types of bonds which are:

10. It is a bond resulting from the electric attraction between a positive ion and a negative ion.

12. It is a bond occurred among the atoms of nonmetals through the participation of each atom with the same number of electrons to complete the outer electron shell of each atom.

13. Types of covalent bond Single covalent bond Double covalent bond Triple covalent bond

14. It is the bond which arises between two nonmetal atoms, where each atom shares the other atom with one electron. It is represented by one line (-) joining the two atoms.

15. It is the bond which arises between two nonmetal atoms, where each atom shares the other atom with two electrons. It is represented by two lines (=) joining the two atoms.

16. It is the bond which arises between two nonmetal atoms, where each atom shares the other atom with three electrons. It is represented by three lines joining the two atoms.