Copper is current voltage above 40 or 200 . copper useful for motor and some medicine
        
             
        
        
        
Answer:
% (COOK)2H2O = 37.826 %
Explanation:
mix: (COOK)2H2O + Ca(OH)2 → CaC2O4 + H2O
∴ mass mix = 4.00 g
∴ mass (CaC2O4)H2O = 1.20 g
∴ Mw (COOK)2H2O = 184.24 g/mol
∴ Mw (CaC2O4)H2O = 146.12 g/mol
∴ r = mol (COOK)2H2O / mol (CaC2O4)H2O = 1
- % (COOK)2H2O = (mass (COOK)2H2O / mass Mix) × 100
 
⇒ mass (COOK)2H2O = (1.20 g (CaC2O4)H2O)×(mol (CaC2O4)H2O / 146.12 g (CaC2O4)H2O)×(mol (COOK)2H2O/mol (CaC2O4)H2O)×(184.24 g (COOK)2H2O/mol (COOK)2H2O)
⇒ mass (COOK)2H2O = 1.513 g
⇒ % (COOK)2H2O = ( 1.513 g / 4 g )×100
⇒ % (COOK)2H2O = 37.826 %
 
        
             
        
        
        
The answer is D. Evaporating water only breaks apart intermolecular bonds like H-bonds and dipole-dipole bonds, and does not change the chemical composition (or intramolecular bonds).
        
                    
             
        
        
        
The atomic number of an element is the same as the number of protons. As long as the atom is neutral, your electrons and protons will be the same number. To find neutrons, you subtract the atomic number from the mass number. 
mass number - atomic number = number of neutrons