Silicon shapes our technological reality because computer chips are made out of silicon. Different computer parts, are made out of silicon chips, tablets, phones, different electronic devices, everything has some silicon in them. Without silicon we would (currently) not have any of those. That is how silicon shapes our technological reality :)
        
                    
             
        
        
        
<span>Answer:
Enthalpy is delta-H-
We need to look at the molecule and determine which bonds are broken adn which bonds are formed.
Bonds that are broken are H-H (from the H2 molecule) and the C=O from acetone.
their energies add up like this: 436 kJ + 745 kJ = 1181 kJ
looking at the bonds formed, these are C-O, O-H, and C-H. these add up to 1229 kJ
solving for delta H by taking the sum of the broken bonds and subtracting the sum of the formed bonds, like so:
1181 - 1229 = -48 kJ</span>
        
             
        
        
        
yes substances Do  react by mass