These are the first 20 elements, listed in order:
H - Hydrogen
He - Helium
Li - Lithium
Be - Beryllium
B - Boron
C - Carbon
N - Nitrogen
O - Oxygen
F - Fluorine
Ne - Neon
Na - Sodium
Mg - Magnesium
Al - Aluminum
Si - Silicon
P - Phosphorus
S - Sulfur
Cl - Chlorine
Ar - Argon
K - Potassium
Ca - Calcium
Try saying these over again and practicing for at least an hour a day!