<p>If you are interested in significant figures in more detail, here are some <a href="https://www.khanacademy.org/math/pre-algebra/decimals-pre-alg/sig-figs-pre-alg/v/significant-figures" target="_blank">good videos</a> to follow on Khan Academy.</p><p>This week we will continue our explorations of matter and energy. We will discuss the sub-atomic particles that govern chemical reactions, isotopes, anions, and cations. We will learn how to name compounds, calculate formula masses, convert between grams and moles, examine periodic trends, and more! An advanced problems set is posted now; that is a longer assignment and is optional unless you would like to be eligible for the Honor’s Track. You can still earn a regular verified certificate without completing the advanced problem sets, so please be sure to keep working on the normal weekly exercises.</p>