Basics
The SI-system, unit converters, physical constants, drawing scales and more.
Acceleration of Gravity and Newton's Second Law
Acceleration of gravity and Newton's Second Law - SI and Imperial units.
Acceleration Units Converter
Converting between units of acceleration.
Air - Thermophysical Properties
Thermal properties of air at different temperatures - density, viscosity, critical temperature and pressure, triple point, enthalpi and entropi, thermal conductivity and diffusivity and more.
Angle Converter
Converting between angle units.
Area Units Converter
Convert between units of area.
British Imperial System
A principal system of units.
Buffer Solutions
Definitions, explanations and examples of how to make buffer solutions.
Bytes, Kilobytes and Megabytes
Computer bytes.
Circles - Circumferences and Areas
Circumferences and areas of circles with diameters in inches.
Concentration Units Converter
Calculator and formulas for conversion between different units of concentration: Molarity, molality, mole fraction, weight percent of solute and grams of solute per liter of solution - descriptive terms for solubility.
Decimal System Prefixes
Prefix names used for multiples and submultiples units.
Density vs. Specific Weight and Specific Gravity
An introduction to density, specific weight and specific gravity.
Designation of Large Numbers
Designation of large number in US vs. other countries.
Dimensionless Numbers
Physical and chemical dimensionless quantities - Reynolds number, Euler, Nusselt, and Prandtl number - and many more.
Drawing Scales
Commonly used blueprint drawing scales.
Efficiency
The measure of usefulness.
Electromagnetic Spectrum
The electromagnetic spectrum with wavelengths and frequencies.
Elements of the Periodic System
The elements of the periodic system with names, symbols, atomic numbers and weights, melting and boiling points, density, electronegativity and electron affinity, and electron configuration.
Empirical Equations
Equations based on observations and experience.
Equilibrium
The mechanical, thermal, electrostatic, phase or chemical states of equilibrium.
Exponents - Powers and Roots
The laws of fractional and integer exponents.
Fractions and Decimal Inches Equivalents
The inches fractional and decimal equivalents.
Frequency, Wavelength and Bands
Bands and their ranges of frequencies and wavelengths.
Fuel Equivalents - Online Calculator
Online fuels energy equivalents calculator for oil, gas and more.
Gallons vs. Pounds of Water Converter
- and vice versa.
Geological Time
Geological periods and time scale.
Heat Capacity
The amount of heat required to change the temperature of a substance by one degree.
Humid Air vs. the Ideal Gas Law
Pressure, temperature and volume in a perfect ideal gas like moist air (air with water vapor).
Inches - Fractional vs. Decimal Equivalents
The decimal equivalents of eights, sixteenths, thirty-seconds and sixty-fourths of an inch.
Inches vs. Feet, Yards and Meters - Conversion Chart
Convert between inches, feet, yards and meters.
Inches vs. mm - Conversion Chart
Convert fractional and/or decimal inches to metric mm - and vice versa.
Length - Online Unit Converter
Convert between length units like meters, feet, inches, nautical miles and more.
Logarithms
The rules of logarithms - log10 and loge for numbers ranging 1 to 1000.
Mass Moment of Inertia
The Mass Moment of Inertia vs. mass of object, it's shape and relative point of rotation - the Radius of Gyration.
Mass vs. Weight
Mass vs. weight - the Gravity Force.
Mixtures, Solutions and Suspensions
Mixtures vs. solutions vs. suspensions.
Mole and the Avagadro's Number
The mole is the SI base unit for an amount of a substance.
Naming Inorganic Binary Compounds
Rules for naming inorganic ionic and covalent types of chemical compounds.
Naming of Organic Compounds
Nomenclature rules for different groups of organic compounds and functional groups, together with examples of use of the rules.
Non-ideal gas - Van der Waal's Equation and Constants
The van der Waals constants for more than 200 gases used to correct for non-ideal behavior of gases caused by intermolecular forces and the volume occupied by the gas particles.
Optical Distance Law
Geometric dilution of light vs. distance.
Ounces and Pounds vs. Grams
Converting ounces (ozs.) and pounds (lbs.) to grams (g).
Parts per Million - ppm
ppm - or parts per million - is commonly used as a unit of concentration.
Periodic Table of Elements
The periodic table of the elements with their atomic numbers.
pH - Basic (alkaline) vs. Acidic
Introduction to pH - the acidic and basic (alkaline) definition.
Physical Constants
Physical constants - SI Units.
Prefixes for Binary Multiplies
IEC International Standard names and symbols
Pressure
Introduction to pressure - online pressure units converter.
Pressure Units - Online Converter
Convert between pressure units like Pa, bar, atmosphere, pound square feet, psi and more.
Pressure vs. Head Unit Converter
Pressure vs. head units - like lb/in2, atm, inches mercury, bars, Pa and more.
Property vs. State
The concept of properties and state.
Pumps, Fans and Turbines - Horsepower
British Horse Power as used for pumps, fans and turbines - and how to convert to other units.
Radians vs. Degrees
Radian is the SI unit of angle. Convert between degrees and radians. Calculate angular velocity.
Radiation Units - Becquerel vs. Curie
Convert between Bequerel and Curie radiation units.
Ratios and Proportions
The relative values between quantities - ratios and proportions.
Real Numbers Algebra
The commutative and associative law for addition and more.
SI System
An introduction to the SI metric system.
Solar System Constants
Properties and data for the Sun, the Earth and the Moon.
Solids - Volumes and Surfaces
The volume and surface of solids like rectangular prism, cylinders, pyramids, cones and spheres - online calculator.
Solubility
The amount of a solute that can be dissolved in a solvent.
Solutions, Molarity and Dilution
Definitions and examples of how to calculate wt%, molarity and how to prepare dilutions.
Some Measuring Units
Commonly used measuring units - like gross, dozen, quire, sheets and more.
Specific Heat - Online Unit Converter
Online specific heat converter with the most commonly used units.
Standard State and Enthalpy of Formation, Gibbs Free Energy of Formation, Entropy and Heat Capacity
Definition and explanation of the terms standard state and standard enthalpy of formation, with listing of values for standard enthalpy and Gibbs free energy of formation, as well as standard entropy and molar heat capacity, of 370 inorganic compounds.
STP - Standard Temperature and Pressure and NTP - Normal Temperature and Pressure
The definition of STP - Standard Temperature and Pressure and NTP - Normal Temperature and Pressure.
Symbols Used to Denote a Chemical Reactions and Process or Condition
Explanation of symbols used as subscripts or superscripts to tell more about the type of chemical reaction, process or condition.
Temperature
Introduction to temperature - including Celsius, Fahrenheit, Kelvin and Rankine definitions - and an online temperature converter.
The Ideal Gas Law
The relationship between volume, pressure, temperature and quantity of a gas, including definition of gas density.
Thermodynamic Key Values Internationally Agreed
Internationally agreed, internally consistent, values for the thermodynamic properties (standard enthalpy of formation, entropy and [H°(298)-H°(0)]) of key chemical substances.
Total and Partial Pressure - Dalton's Law of Partial Pressures
How to calculate total pressure and partial pressures for gas mixtures from Ideal Gas Law.
Trigonometric Functions
Sine, cosine and tangent - the natural trigonometric functions.
Unit Converter with commonly used Units
Common converting units for Acceleration, Area, Density, Energy, Energy per unit mass, Force, Heat flow rate, Heat flux, Heat generation per unit volume and many more.
Unit Factor Method
Convert between units with the unit factor or factor-label method
USCS - United States Customary System Units
An overview of the United States Customary System Units - Imperial Units.
Vector Addition
Online vector calculator - add vectors with different magnitude and direction - like forces, velocities and more.
Velocity Units - Online Converter
Convert between common velocity and speed units.
Volume Converting Chart - Gallons vs. Cubic Feet vs. Cubic Meters and more.
Convert between volume units like U.S. liquid gallons, U.K. liquid gallons, cubic feet, cubic metre and more.
Volume Flow - Online Unit Converter
Convert between volume flow units like gpm, liter/sec, cfm, m3/h.
Volume Units Converter
Convert between common volume units like cubic metre, cubic feet, cubic inches and more.
Water Content in Food and other Products
Water content before and after drying - in food and other products cork, grain, soap, peat, wood and more.
Water Pressure vs. Head
Pressure in pounds per square inch (psi) vs. head in feet of water (fth2o).
