Ellen Y

We found 6 articles

How to solve an empirical formula problem
In this blog post, we will review how to determine the empirical formula of a compound using the mass percentages of the elements from which it is formed.
Quantum numbers
In this blog post, we explore the four quantum numbers, which allow us to describe the properties of each electron within an atom. According to the Pauli Exclusion Principle, no two electrons can share the same combination of quantum numbers. A carbon atom has six electrons, for example, and each of these electrons can be described by one of six ...
A painless introduction to VSEPR theory
Today we will discuss VSEPR (pronounced “vesper”), which stands for valence-shell electron-pair repulsion. The basis of VSEPR is that the electrons in bonds and lone pairs repel each other. To minimize the instability that results from these repulsions, a molecule will adopt the shape that places electron groups as far apart as possible. VSEPR ...
Drawing the chair conformation of a pyranose ring
Welcome back! In this blog post, we will complete the following example problem:
How to balance redox reactions in acidic and basic solutions
Balancing redox reactions is an essential skill for the Chemical and Physical Foundations section of the MCAT, the GRE Chemistry Subject Test, and the AP Chemistry Exam. Today, we will learn how to use the half-cell method for balancing redox reactions in acidic and basic solutions. We will first balance a redox reaction in acidic solution, then ...
Working with lenses and mirrors: how to draw a ray diagram
Ray diagrams can look intimidating, but they don’t have to be! In this blog post, we will tackle five examples of ray diagrams.