The Brownian Motion – Nada El Annasi / #race2space2020

Imagine with me, drinking a cup of tea while sitting on the balcony in the morning. And the house is perfumed by an incense stick that your mother ignited. What a feeling! Right? But have you ever asked yourself how does tea flavor spread from the tea bag throughout a cup of hot water? And […]

Polar Molecules Tutorial: How to determine polarity in a molecule

in which we will explore how bond polarity affects the polarity of a molecule so what is polarity? First molecules are neutral; the entire molecule has an equal amount of protons and electrons; with that in mind if the negative charge, the electrons in a molecule, are evenly distributed around the molecule, then it is […]

Empirical Formula vs Molecular Formula Calculations for the MCAT

Leah here from and in this MCAT video we’re going to look at Empirical versus Molecular Formula. You can find this entire video series along with the reactions and stoichiometry practice quiz by visiting my website The molecular formula as the name implies gives us the formula or the equation for a specific […]

Why is Carbon the Key to Life? (On Earth, Anyway)

No matter how green, how furry, how small, how big, or how weird, all known life forms are based on the chemistry of one element: carbon. But why carbon? And if we look out to the stars,, could there be a fundamentally different kind of life out there? Questions like these are really hard to […]

Mole and Avogadro’s Number in MCAT General Chemistry

Leah here from and in this video we’re going to look at the mole concept in avogadro’s number. What is a mole? We’re not referring to a little rodent and we’re not referring to that thing that can show up on your skin and definitely not referring to a spy though that would be […]

Smart Alex – Amino Acids and Valency of Elements

Two carbon atoms, two oxygen atoms, one nitrogen atom and four hydrogen atoms. Vinegar All the bonds are used up That’s what amino acid is made of The number of bonds that an atom can make is called it’s valency Hydrogen has a valency of one Oxygen two Nitrogen three and carbon four bonds with […]