False, gravity is a force, matter has mass and volume.
Answer:
I can list four. These are the main ones.
Bolling
Filtration
Distillation.
Chlorination
Explanation:
Answer: When water freezes it gets larger and becomes a solid but it still weighs the same as when it was a liquid form. When it becomes larger it takes up space but makes it less dense. Ok so getting to the point- oil unlike water becomes more dense when frozen so this is why oil sinks in water. Sorry if this was confusing but I hope it helped have a great day and god bless you :3

The emission spectrum of a chemical element or chemical compound is the spectrum of frequencies of electromagnetic radiation emitted due to an atom or molecule making a transition from a high energy state to a lower energy state. The photon energy of the emitted photon is equal to the energy difference between the two states. There are many possible electron transitions for each atom, and each transition has a specific energy difference. This collection of different transitions, leading to different radiated wavelengths, make up an emission spectrum. Each element's emission spectrum is unique. Therefore, spectroscopy can be used to identify elements in matter of unknown composition. Similarly, the emission spectra of molecules can be used in chemical analysis of substances.