One possible answer could be that a chemical reaction has occurred.
        
             
        
        
        
Answer:
M is increased loudness
O is decreased loudness
N is decreased pitch
P is increased pitch
Louder soundwaves ten to have longer and deeper waves visa versa.
Increased pitch tends to have shorter soundwaves. visa versa
 
        
             
        
        
        
Answer:
Conduction, Convection and Conduction
Explanation:
 
        
             
        
        
        
Answer:
It conducts electricity
It conducts heat
Water is needed for rusting
Explanation:
Metals refer to elements that are found towards the left hand side of the periodic table of elements. They are found in groups 1- 13 and few of them are also found at the bottom of groups 14 and 15.
Now these metal have certain properties that are general to all of them. two of these properties listed among the options in the question are;
i) They conduct electricity
ii) They conduct heat
These properties apply to all metals universally.
Rusting is an electrochemical reaction in which hydrated iron III oxide is formed. In the electrochemical reaction, water in intimately involved in the process. Hence; oxygen and water are required for rusting to take place.