If it is just ratio you must just put the mass number on the either side of the symbol ‘:’ and cancel but the same process is not used to find simplest ratio
Double replacement i believe
No He believed tiny particles were invisible and couldn't be changed....So No The person that believed in this was Dalton .
-They can conduct heat
-They can conduct electricity
-They are typically stronger than non metals
Hope this helps, have a nice day! :)