Answer:
chlorine atom
A chlorine atom has 17 protons, 18 neutrons, and 17 electrons.
Explanation:
Sawing a board in half is a physical change not a chemical change the board doesnt change wood or whatever material it is is still would still be wood
If it were burned it would be a chemical change but its properties stay the same atomically so thats why its not a chemical change.
the nebular theory states that the solar systems developing <u><em>rotations </em></u>revolve around sun. it is located in the milky-way. revolving around the <u><em>sun</em></u>, with <u><em>gravity</em></u> pulling it, an interstellar cloud of dust and gas, is formed. (i.e. the nebula that we are speaking)
this formation is a<u><em> protostar</em></u>. the idea in the theory states that the <u><em>nebula</em></u> has flattened into a <u><em>disk</em></u> called the "protoplanetary disk"; and over time, the debreis eventually formed this disk. (i.e. creating the milky-way)
hopefully this helped, thank you!! :D