So back in 1665 Robert hook was able to view cells and describe them along with pictures, the reason he was able to see cells was because the microscope was invented a bit before, which allowed him to think about things differently, he was looking at a cork and saw squared objects, these objects were cells, according to him.
So while the cork was the reason he discovers cells on it in the first place,
The microscope was what allowed him to do that
So it’s (HOOKE LOOKING AT A CORK)
And it’s (THE INVENTION OF THE MICROSCOPE)
The amount of physical material in an object
Answer:
electrons located outside the nucleus
Explanation:
electrons are said to be located outside the nucleus of an atom and are in orbit around the nucleus.
according to Bohr in 1913.
Counting gives an exact number and exact numbers have infinite sig figs.
Explanation:
Magnesium has atomic number 12. It will be distributed in K, L, M shell in the following way:
K shell can accommodate a maximum of 2 electrons.
L shell can accommodate a maximum of 8 electrons and
M shell will accommodate 2 electrons
So the configuration becomes 2, 8,3
