What subatomic particle has negligible mass and travels around outside the nucleus?

Why does his teacher ask him to balance the equation by including the correct coefficient

How have the greenhouse gasses increased from the year 2000 to 2018

Ill give brainiestif one neutron initiates a fission event that produces two neutrons in the products, how many new reactions can now be initiated? if each of the neutrons produced in the first fission event then initiates a fission event that produces one neutron in the products, how many new reactions can now be initiated by each neutron? how many neutrons in total were produced by the two fission events described?