Answer:
The density of the substance is 1.0611 
Explanation:
The density of a substance is a characteristic property that matter, whether solids, liquids or gases, has to be compressed in a given space, that is, it allows us to measure the amount of mass in a certain volume of a substance.
Density is expressed as follows:

In this case:
- density: ?
- mass: 21.1164 grams
- volume: 19.9 cm³
Replacing:

density= 1.0611 
<u><em>The density of the substance is 1.0611 </em></u>
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Bohr's model is different from Rutherford's model by Bohr's model has 150 words , fundamental principles. also Rutherford's model does not have 150 words and fundamental principles. <span />
Ultraviolent radiation i believe
Answer:
Aristotle's idea was to classify living beings.
I think so