Answer- The particles in a solid gain enough energy to overcome the bonding forces holding them firmly in place. Typically, during melting, the particles start to move about, staying close to their neighbouring particles, then move more freely.
        
             
        
        
        
Oxygen had 6 valence electrons
        
             
        
        
        
Answer:
SiF4 is not a polar covalent bond.
Explanation:
SiF4 is a nonpolar molecule because the fluorine's are arranged around the central silicon atom in a tetrahedral molecule with all of the regions of negative charge cancelling each other out.
 
        
             
        
        
        
Answer:
Chemistry is used almost everywhere you go. from the car you use to get to work (gasoline burning) to the nuclear reactors that power many homes ( uranium becoming unstable to product electricity.