Each guide here takes one practical job, from mixing laundry detergent to cleaning lab glassware to building a classic experiment on a kitchen table, and walks through it step by step. Every guide also explains the science behind each step, so you know why it works and what to change when it does not.
Every guide opens with a short answer and an at-a-glance card listing the time, materials and steps. Some include a calculator that scales the recipe or measurement to your own numbers.
Around the houseHow to Make Dish Soap (With Calculator), According to ScienceThree homemade dish soap recipes with a calculator that checks your water hardness, plus why vinegar ruins castile soap.Read the how-to →
Around the houseHow to Make Laundry Detergent (With Calculator), According to ScienceMix laundry powder or liquid from soap, washing soda and borax, with a calculator for your loads and water hardness.Read the how-to →
Experiments at homeHow to Do the Double-Slit Experiment at Home (and Why the Bands Appear)See light interfere with a laser pointer, foil and two razor blades, then measure your laser's wavelength.Read the how-to →
Lab skillsHow to Clean Petri Dishes: Glass, Plastic and Used Agar PlatesClean and sterilize glass and plastic petri dishes and dispose of used agar plates safely.Read the how-to →
Lab skillsHow to Clean a Bunsen Burner in 6 StepsTake apart, clean and reassemble a Bunsen burner so it burns with a clean blue flame.Read the how-to →Looking for calculators and interactive models instead? See the 33Science tools.