I believe the correct response would be A. The cumulative nature of science. How experimental evidence and ideas made by many scientists have accumulated and or built up to have a more understandable and or clear view of a particular scientific topic, and or principle.
207 is the mass number. 82 would be the atomic number
Answer:
Fe2O3 + 3CO → 2Fe + 3CO2
Explanation:
the numbers in front are the numbers you need
Answer:
Na ·
Explanation:
Hello!
In this case, since the Lewis dot structure of any element illustrates the number of valence electrons at the outer shell; we can set up the electron configuration of sodium to obtain:

We can see there is only one valence electron, for that reason the Lewis dot structure is:
Na ·
Whereas the dot represents the valence electron.
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I think it is the third statement
‘A unit is made up of two or more atoms’