Science Common Sense


1730 - What are the commonly used methods and principles for identifying substances?

There are several methods to identify substances. Here are a few common ones:

  1. Observation: Look at the substance's color, texture, and smell to get an idea of what it might be.
  2. Boiling and Melting Points: Heat the substance to see at what temperature it melts or boils. Different substances melt and boil at different temperatures.
  3. Chemical Tests: Mix the substance with other chemicals to see what happens. For example, adding vinegar to baking soda makes it fizz.
  4. Chromatography: Separate the substance into its different parts to identify what's in it.
  5. Density: Measure how heavy the substance is compared to its size. Different substances have different densities.

Some important principles to keep in mind when identifying substances include:

  1. The Law of Conservation of Mass: Matter can't be created or destroyed, only changed.
  2. The Law of Definite Proportions: A substance always has the same percentage of elements.
  3. The Law of Multiple Proportions: When elements combine to form different compounds, they do so in simple ratios.

These methods and principles can help you figure out what a substance is and what it's made of.