How to find an elements atomic weight

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?

What is the approximate mass of 25 cm3 of silver, if the density is 10.5 g/cm3? a. 0.42 g b. 2.4 g c. 42 g d. 260 g

Equal volumes of h2 and o2 are placed in a balloon and then ignited. assuming that the reaction goes to completion, which gas will remain in excess? 2h2 + o2 → 2h2o a. both are in equal proportion b. oxygen c. water d. hydrogen