Iodine-131 has a half-life of 8 days what fraction of the original sample would remian at the end of 32 days

In the millikan oil drop experiment they determined that every drop had a charge which was a while number multiple of -1.60x10^-19. if a drop has a total charge of -9.60x10^-19 then how many excess electrons are contained within the drop?

When a nucleus absorbs a neutron and then breaks apart, there are many products of the reaction. what is not a product of a nuclear fission reaction

As air becomes more dense, (select all that apply) o. air weighs less o. gas molecules are closer together o. air is colder o. air weighs more o. gas molecules are further apart o. air is hotter