Learn about phlogiston theory in chemistry history. Discover what phlogiston is and how scientists discovered the true nature of combustion.

# Yearly Archives: 2023

Learn how to calculate circle revolutions and the distance circles travel. Also discover the coin rotation paradox and its applications.

## Circle Revolutions and the Coin Rotation Paradox

Get arsenic facts. Learn about the element's properties, uses, and sources. Find out how arsenic poisoning works.

## Arsenic Facts – Element As or 33

Learn about piezoelectricity and the piezoelectric effect. Get examples of piezoelectric materials and learn how piezoelectricity works.

## Piezoelectricity and the Piezoelectric Effect

Get the allele definition and examples in genetics. Learn about the difference between alleles and genes and their location on chromosomes.

## Allele Definition and Examples

Learn about blood types, including A, B, AB, O and Rh+ and Rh-. See which blood type is the universal donor and universal recipient.

## Blood Types – A, B, AB, O, Rh

Learn how to add fractions. Get step-by-step instructions and examples using simple and mixed fractions and one with negative numbers.

## How to Add Fractions

Get facts about the element selenium, with symbol Se and atomic number 34. Learn about its properties, uses, health effects, and sources.

## Selenium Facts – Element Se or 34

Learn about mammals. Discover their characteristics, get examples, and learn about different orders of mammals.