A certain radioactive isotope has a half-life of approximately 900 years. How many years to the nearest year would be required for a given amount of this isotope to decay to 30% of that amount?

You can decrease the resistance of a length of wire by

First answer marked as brainiest which is the correct equation describing the first law of thermodynamics? a) when the internal energy of a system changes, it equals the amount of heat added plus the work done. b) when work is done by the piston, it is equal to the heat added plus the change in internal energy of the system. c) when heat is added to the system, it is equal to the amount of work done by the piston plus the change in internal energy of the system.

Which substance partical has negligible massand travels around outsidethe nucleus