Caffeine is a stimulant, which means it increases activity in your brain and nervous system. It also increases the circulation of chemicals such as cortisol and adrenaline in the body. In small doses, caffeine can make you feel refreshed and focused

Serotonin controls your mood and is responsible for happiness. It helps regulate when you sleep and wake, helps you think, maintains your mood, and controls your sexual desire

Dopamine is responsible for allowing you to feel pleasure, satisfaction and motivation. When you feel good that you have achieved something, it's because you have a surge of dopamine in the brain.

Caesium metal is highly reactive and pyrophoric. It ignites spontaneously in air, and reacts explosively with water even at low temperatures