Answer:
hydrogen and oxygen combine explosively in a single raction 
Explanation:
The reason is Molecules of hydrogen react with oxygen violently to break the initial molecular bonds and form new one between the atoms of the two elements. The reaction results into an explosive release of energy and the production of water because the products of the reaction are at a lower energy level
 
        
             
        
        
        
Answer: refer to, uofmhealth.org/health-library/tx4097abc
Explanation:
you should find your answer there
 
        
             
        
        
        
(Basic) kinetic energy and potential energy
Hope this helped :)
        
             
        
        
        
Answer:
 Pteridophytes are vascular plants but they do not produce flowers and seeds which mean their source of reproduction is unknown or hidden. 
On the contrary, Spermatophytes as the name indicates, are seed bearing plants. They produced seeds and flowers. Examples are flowering plants, cactus, leather flower, buttercup and may more.
Explanation:
 
        
             
        
        
        
Was AA, KK, and TT correct?