Atoms and molecules

2,317 views

Published on

Published in: Technology, Education
0 Comments
3 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
2,317
On SlideShare
0
From Embeds
0
Number of Embeds
2
Actions
Shares
0
Downloads
136
Comments
0
Likes
3
Embeds 0
No embeds

No notes for slide

Atoms and molecules

  1. 1. ATOMS AND MOLECULES By, Abhijith Rajeev,Shibin P shaji,Dollsy Jeorge,Priya Jose
  2. 2. OUTLINE •Laws of Chemical Combination •Law of Conservation of Mass •Law of Constent Proportion •Atom •Molecule
  3. 3. Introduction What you mean by atom and molecule?  Atom: • Smallest particle of element • May or may not exist independtly • May or may not have properties of matter  Molecule: • Smallest particle of compound • Always exist independtly • Always posses the properties of matter
  4. 4. Law of chemical combination • atoms exist in the combined form I. Law of conservation of mass II. Law of constent proportion
  5. 5. Law of conservation of mass • A Lavoisier-father of chemistry • mass can be neither created nor be destroyed
  6. 6. Law of constent proportion • Joseph Proust: pure chemical compound contain element in definite proportion by mass
  7. 7. ATOM • Atomic symbols:short hand reperesentation for the name of element Eg:H - hydrogen,Ne – neon • Atomic mass:mass of an atom of an element Eg:H - 1,Ca - 16 • Atomic mass unit:mass of one twelth of mass of 1 carbon 12 atom • Average atomic mass:atomic mass of isotopes Eg:H-1.008 and it is taken as 1 unit
  8. 8. • Gram atomic mass: atomic mass expressed in grams Eg:C – 12g , N-14g • Atomic combination: atoms are bonded together by strong forces of attraction and the new species is called molecules.Molecules are of 2 types I. Homoatomic: same type of atoms II. Heteroatomic: 2 or more types of atoms • Ions:atom having +ve or –ve charge I. Cation: +ve charged ion II. Anion: -ve charged ion
  9. 9. MOLECULE • Molecular mass: mass of the molecules of a chemical compound.  Expressed in amu  Determined by adding the individual atomic mass Eg:molecular mass of NH3 =atomic mass of N + 3 * atomic mass of H = 14+[3*1] =17 amu • Gram molecular mass: molecular mass expressed in grams  Numericlly equal to molecular mass in amu  Eg: I g molecule of H20 =18g
  10. 10. MOLE CONCEPT • 1 Mole = 6.023 * 1023 number of particles • 1 mole of any substance contain avagrado number[6.023*1023] of particles which have weight equvalent to atomic mass • Number of moles = total mass molecular mass N = W M
  11. 11. Conclusion • All elemnts are made up of atom • Atoms have differenr mass and organisation • Electrons,protons,neutrons make atoms • Molecule-2 or more atom combined to form single species

×