वह पदार्थ जिसे सामान्य रासायनिक अभिक्रियाओं द्वारा सरल पदार्थों में विभाजित नहीं किया जा सकता है, कहलाता है:

If a sample of air is compressed to half its original volume at constant temperature, which of the following statements is correct?

Substances that are composed of two or more elements chemically combined in a fixed proportion by mass are called ________.

An alloy is a ________.