The atom is krypton and its symbol is Kr.
the mass number is 41 + 36 = 77
its charge is 0 as it is a noble gas.
The scientific geographic name is usually a great election
Explanation:
Speed depends on your referential. Some chemical reactions can take only a fraction of a second while others take days.
Combustion is typically very fast. You can also try and look at lithium+water which is a dangerous, fast and exothermic reaction.