CHEMICAL FORMULAE  AND EQUATIONS
An atom size is very  tiny and descrete How to determine the  mass of atom?
Relative Atomic Mass,A r <ul><li>=  the mass of one atom of the element </li></ul><ul><li>1/12  x  the mass of carbon-12 a...
Why pick carbon-12 as standard? <ul><li>Hydrogen-1 </li></ul><ul><li>Exist as gas at room temperature </li></ul><ul><li>Ha...
<ul><li>Carbon-12 </li></ul><ul><li>Exist as solid at room temperature </li></ul><ul><li>Easily to handle </li></ul><ul><l...
Relative Atomic Mass,A r <ul><li>=  the mass of one atom of the element </li></ul><ul><li>1/12  x  the mass of carbon-12 a...
Relative Atomic Mass,A r = Nucleon number  (p+n)
<ul><li>Adding up the Ar of all atoms in a molecule </li></ul><ul><li>Example: MgCO 3  ;  </li></ul><ul><li>  Ar Mg = 24 ,...
Example: HPO 4 :  ;  Ar H = 1 , P=31 , O=16  Mr  of  HPO 4   =(1x1)+(1x31)+(4x16)   =1+31+64   =96
Let’s try!
Upcoming SlideShare
Loading in …5
×

Chapter 3 chemical formulae

2,848
-1

Published on

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

No Downloads
Views
Total Views
2,848
On Slideshare
0
From Embeds
0
Number of Embeds
2
Actions
Shares
0
Downloads
77
Comments
0
Likes
2
Embeds 0
No embeds

No notes for slide

Chapter 3 chemical formulae

  1. 1. CHEMICAL FORMULAE AND EQUATIONS
  2. 2. An atom size is very tiny and descrete How to determine the mass of atom?
  3. 3. Relative Atomic Mass,A r <ul><li>= the mass of one atom of the element </li></ul><ul><li>1/12 x the mass of carbon-12 atom </li></ul>
  4. 4. Why pick carbon-12 as standard? <ul><li>Hydrogen-1 </li></ul><ul><li>Exist as gas at room temperature </li></ul><ul><li>Hard to handle </li></ul><ul><li>Oxygen-16 </li></ul><ul><li>Exist in three isotopes O-16, O-17,O-18 </li></ul>
  5. 5. <ul><li>Carbon-12 </li></ul><ul><li>Exist as solid at room temperature </li></ul><ul><li>Easily to handle </li></ul><ul><li>Also found three isotopes:C-12, C-13, C-14 but the C-12 is the most abundant, about 98.89% </li></ul>Why pick carbon-12 as standard?
  6. 6. Relative Atomic Mass,A r <ul><li>= the mass of one atom of the element </li></ul><ul><li>1/12 x the mass of carbon-12 atom </li></ul><ul><li>Example: A r for Magnesium = 24 . </li></ul><ul><li>1/12 x 12 </li></ul><ul><li>= 24 </li></ul>
  7. 7. Relative Atomic Mass,A r = Nucleon number (p+n)
  8. 8. <ul><li>Adding up the Ar of all atoms in a molecule </li></ul><ul><li>Example: MgCO 3 ; </li></ul><ul><li> Ar Mg = 24 , C=12 , O=16 </li></ul><ul><li>Mr of MgCO 3 = (1x24)+(1x12)+(3x16) </li></ul><ul><li>=24+12+48 </li></ul><ul><li>=84 </li></ul>Relative Molecular Mass,Mr
  9. 9. Example: HPO 4 : ; Ar H = 1 , P=31 , O=16 Mr of HPO 4 =(1x1)+(1x31)+(4x16) =1+31+64 =96
  10. 10. Let’s try!
  1. Gostou de algum slide específico?

    Recortar slides é uma maneira fácil de colecionar informações para acessar mais tarde.

×