Science Notes Posts

Periodic Table of Radioactive Elements 1
Technetium is a radioactive element, with no stable isotopes. With an atomic number of 43, it is the lightest unstable element. All of the elements surrounding it on the periodic table have at least one stable isotope. What is it about technetium that makes it special? The short answer is […]

Why Is Technetium Radioactive?

Periodic Table Metals - 2017 5
Most elements can be considered metals. They are grouped together in the middle to the left-hand side of the periodic table. The metals consist of the alkali metals, alkaline earths, transition metals, lanthanides, and actinides. Properties of Metals The metals share several common properties, including: solid at room temperature (with […]

List of Metals

Percent error is the percent difference between a measured and expected value. (image credit: Sherman Geronimo-Tan) 9
Percent Error Definition Percent error, sometimes referred to as percentage error, is an expression of the difference between a measured value and the known or accepted value. It is often used in science to report the difference between experimental values and expected values. The formula for calculating percent error is: […]

Calculate Percent Error

CPK-Jmol Periodic Table
Chemistry departments often have kits of plastic balls to stick together to represent atoms and their arrangement in molecules. These kits come with several different colors to easily distinguish one element from another. The choice of color for each atom is not arbitrary. The color code of these atoms is known as CPK colors.

Molecule Atom Colors – CPK Colors