There's a song on YouTube about it (with pictures) and it helps me remember some-
Hydrogen, helium ,lithium, brelium, boron, carbon, nytrogen, oxygen, fluoride neon, sodium, magnesium, aluminum, silicon, phosphorus, sulphur, chlorine, argon, potassium, calcium.
First 20 Thats all I can memorize but I don't think u should have to memorize ALL of them....