Answer:
Pyrophoricity is a property of metals and oxides of lower oxidation states, including radioactive ones, in which they spontaneously ignite during or after stabilization.
Answer:

Explanation:
Combination reactions are the reactions in which two or more atoms/ molecules combine to give a single product.
Aluminum metal combines with iodine to given aluminium iodide.
Aluminium has a valency of 3 and iodine has valency of 1, so the formula is 
The reaction is shown below as:

Answer: both numbers are 2
Explanation: