# Measurement

## How Much Does a Gallon of Water Weigh? Easy Calculation

Question: How much does a gallon of water weigh? Answer: A US gallon of water weighs 8.34 lbs or 3.78 kg at 62 °F (17 °C). An imperial gallon (UK) weighs 10.022 lbs or 4.546 kg, at its most dense temperature, which is 2.20456 lbs / L at 4 °C […]

## Why There Is No Degree in Kelvin Temperature2

When you write a temperature using the Celsius, Fahrenheit, or Rankine scales, you include a degree symbol. Have you ever wondered why there is no degree in Kelvin? The answer has to do with the definition of a degree. A degree is a change in temperature that is measured against a […]

## Physical Constants, Prefixes, and Conversion Factors

Here are some useful physical constants, conversion factors, and unit prefixes. They are used in many calculations in chemistry, as well as in physics and other sciences. Useful Constants Acceleration of Gravity 9.806 m/s2 Avogadro’s Number 6.022 x 1023 Electronic Charge 1.602 x 10-19 C Faraday Constant 9.6485 x 104 […]

## SI Units Word Search Puzzle1

This SI units word search puzzle contains vocabulary words dealing with base and derived SI units used in science. These terms can be found horizontally, vertically, and diagonally. Click the image for full-size or download the PDF and give it a try. If you would like some help finding some of the terms, take a peek […]

## Printable Protractors1

Have you ever needed a protractor but couldn’t find one? Here’s a pair of printable protractors available whenever you want one. These printable protractors have the added benefit to be transparent images which makes them extremely useful to print on transparencies. This allows you to look through the protractor while you […]