An unknown radioactive element decays into non-radioactive substances. in 420 days the radioactivity of a sample decreases by 39 percent.1.what is the half-life of the element? 2.how long will it take for a sample of 100 mg to decay to 46 mg?

The magnetic field inside a superconducting solenoid is 4.50 t. the solenoid has an inner diameter of 6.20 cm and a length of 26.0 cm. determine (a) the magnetic energy density in the field and (b) the energy stored in the magnetic field within the solenoid.

You win the lottery and decide to impress your friends by exhibiting a million-dollar cube of gold. at the time, gold is selling for $ 426.60 per troy ounce, and 1.0000 troy ounce equals 31.1035 g. -how tall would your million-dollar cube be? en cm

What is a subatomic particle with a negative charge and very little mass?