How can you measure 20 mg. of salt?
To measure 20 mg of salt, you will need to use a scale or balance that can measure small amounts accurately. Here's a step-by-step guide on how to do it:
1. Obtain a precise digital scale or balance that can measure in milligrams (mg). You can find these types of scales at pharmacies, scientific supply stores, or online.
2. Place a small container, such as a weighing boat or a glass weighing dish, on the center of the scale.
3. Make sure the scale is properly calibrated. If it needs calibration, follow the instructions of the manufacturer to calibrate it correctly.
4. Zero the scale. This means resetting it to 0 before weighing anything. Most digital scales have a "Tare" button that you can press to set the reading to zero with the container on it. If your scale doesn't have a tare function, you can manually subtract the weight of the container later.
5. Carefully add salt to the container. Use a tool like tweezers or a micro spoon to avoid adding extra weight from your fingers. Add the salt slowly until the scale displays a weight of 20 mg.
6. If you used a weighing container, remember to subtract its weight from the total. For example, if the container weighs 5 mg, the actual weight of salt will be 20 mg - 5 mg = 15 mg.
By following these steps, you should be able to measure 20 mg of salt accurately using a digital scale or balance that can measure small quantities.