Todd Helmenstine


About Todd Helmenstine

Todd Helmenstine is the physicist/mathematician who creates most of the images and PDF files found on sciencenotes.org. Nearly all of the graphics are created in Adobe Illustrator, Fireworks and Photoshop. Todd also writes many of the example problems and general news articles found on the site.

Color Periodic Table without Names - 118 Elements
Here is a 118 element periodic table without names of the elements included on the table. Color Periodic Table without Names The first table is a color version of the periodic table without the element names included. This table has the atomic numbers, element symbols, and atomic masses rounded to […]

Printable Periodic Table without Names


Aurora Borealis
Nanometers ( nm ) and angstroms ( Å ) are linear measurements used to describe very small distances. These measurements often appear in applications of spectroscopy and the sizes of atoms. This example problem shows how to convert nanometers to angstroms. Convert Nanometers to Angstroms Example Problem Question: The vivid […]

How to Convert Nanometers to Angstroms


Thermometer with Celsius and Fahrenheit (Ged Carroll)
Discussing the weather with Americans often includes the need to convert Celsius to Fahrenheit temperature scales. Friends in Europe complain of heat when the temperature is 35° and my first thought is 35° is a pretty cold day. 35 °F is barely above the freezing point of water. I also know […]

How to Convert Celsius to Fahrenheit



Cubic Feet Meter
A cubic foot is an imperial volume measurement equal to a cube with sides equal to one foot in length. The unit often appears in industrial applications involving liquids and gases. Converting this unit to SI units does not come up all that often, so the conversion factor is not really […]

How to Convert Cubic Feet to Liters


This example problem illustrates the steps to convert from gallon to liter. This problem is a common homework conversion to help students move from one system of measurement to another. In this case, the liter is an SI unit of volume and the gallon appears in two different forms: the […]

Gallon to Liter Conversion Example Problem


Gas Tank for Density of Ideal Gas Example
A common homework problem involving the ideal gas law is finding the density of an ideal gas. The idea of the problem is to bring in previously learned concepts of density and molecular mass into problems involving mostly pressures, volumes, and temperatures. This example problem will show how to find […]

Density of an Ideal Gas Example Problem – How to ...