Atoms and Molecules (October 30,2009)

We had a 45min block, but was still able to cover the lesson plan! :)

For monoatomic (one atom) elements
-->a molecule = an element
ex. Ne = Ne
Diatomic elements:
Molecule-------Element
Cl2--------------Cl
Molecules of Compounds ---> Molecule
H-O-H -------H2O-----------2 'H' atoms in 1 molecule; 1 'O' atom in 1 molecule

EXAMPLES
1. Write Ammonium Carbonate (NH4)2CO3
N:2---------H:8----------C:1--------O:3
Moles <---> Molecules
6.02x10^23moles/1mol -------- 1mol/6.02x10^23

2. How many moles are in 0.25 mol of Co2?
0.25mol x 6.02x10^23/1mol = 1.505 x 10^23molec

3. 5.1772 x 10^24molecules of H2O = ? moles
5.1772 x 10^24molecules (1mol/6.02 x 10^23 molecules) = 8.6 mol

4. Find the number of 'H' atoms in 4.0 mol of ammonia (NH3)
moles---->molecules---->H atoms
4.0mol x 6.02 x 10^23/1mol = 2.41 x 10^24molecules x 3= 7.22 x 10^24 'H' atoms