1-Structure of Matter
1-Structure of Matter
1-Structure of Matter
Structure of matter
Dr/Diaa Elmwafy
The atom is composed of:-
A-The nucleus: protons (+ve)
neutrons(uncharged)
B-Electrons (-ve)
The atom is the basic unit of internal structures
Strong intramolecular
State of matter
Free movement of electrons → ↑ energy →↑ IAD
Gas > Liquid > Metal
Structure of solids
Solid substances are classified according to
the internal atomic structure, depending on
the regularity of the atoms or molecules in
the three spatial directions, into:-
1-Crystalline
2-Amorphous (non crystalline)
3-Semi Crystalline (Mesomorphous)
1-Crystalline
The atoms are arranged regularly &
repetitively in the 3-dimensions.
BCC has 2 atoms per unit cell [ (8x1/8) + 1] , e.g. iron, chromium.
3-Face centered cubic: (FCC)
The unit cell has an atom at each corner of
the 8 corners of the cube and another atom
at the center of each face of the unit cell.
At the center of each face the atom share 2
unit cells & thus its value may be as a ½
atom→ There are 4 atoms per unit cell in
FCC.
3-Plane defects:
Such as grain boundaries in metals
Thank you