Answer:
Pure compounds include elements and compounds where a combination of two or more pure substances is a mixture. Only one type of atom comes in the form of a pure element. Multiple atoms consist of a molecule and different atoms consist of a compound. These are all pure substances and individually.
ANSWER
A standard light microscope is used to view living organisms with little contrast to distinguish them from the background, which would be harder to see with the electron microscope.
Electron microscopes can be used to examine not just whole cells, but also the subcellular structures and compartments within them.
Oxygen is 21% and nitrogen is 78% so combined is 99%
There are some methods that differentiate waves; one thing is by its medium.
Electromagnetic waves did not require a medium for transmission such as in a
vacuum while mechanical waves require a medium to travel such as air, water or
anything that can serve as a transmission aid.
The most common sample of EM waves in
telecommunication is radio,
light and infra-red signals. An example of a mechanical wave is a sound
wave, which requires air to travel. Oscillating molecules made the
sound waves.
