Monthly Archives: March 2020

There are many molecules and atoms in a drop of water.
Have you ever wondered how many molecules or atoms are in a drop of water? This is a common chemistry problem students solve because it deals with several important concepts, including chemical formulas, unit conversions, volume, mass, density, using the periodic table, the mole, and Avogadro’s number. Here is a […]

How Many Molecules and Atoms in a Drop of Water?

Don't Drink Hand Sanitizer
Some people drink hand sanitizer to get a buzz or get drunk. Kids have been known to lick hand sanitizer off their hands, resulting in a panicked call to Poison Control. How dangerous is it to drink hand sanitizer? What are the risks? What do you do if a child […]

Can You Drink Hand Sanitizer?

Pi is an irrational number.
The number π or pi is a mathematical constant that is the ratio of a circle’s circumference to its diameter (π = C/d). The ratio is a constant no matter what size of circle is used. Pi is also called Archimedes’ constant. Although pi is often approximated as 3.14159, its […]

Pi Facts – What Is the Number Pi?

Bath bombs dissolve in an endothermic reaction
An endothermic reaction is a chemical reaction that absorbs heat from its environment. Like any chemical reaction, an endothermic reaction requires activation energy to proceed. Then, it continues to absorb energy. Such reactions feel cold. In contrast, exothermic reactions release more heat than they absorb and feel hot. Not all […]

Easy Endothermic Reaction Demonstration

Adding Positive Negative Numbers
Positive and negative numbers are two broad classes of numbers that are used in math and also everyday transactions, like managing money or measuring weight. A positive number has a value greater than zero. Its sign is positive, but it is usually written without a plus sign in front of […]

Rules for Positive and Negative Numbers