Actinium-226 has a half-life of 29 hours. If 100mg of actinium-226 disintegrates over a period of 58 hours, how many mg of actinium-226 will remain?

Which force is most responsible for binding together an atom's protons and neutrons? electrostatic gravitational nuclear magnetic

There is a theory that indicates that dinosaurs became extinct when about 65 million years ago, a large asteroid hit the earth surface. dust caused by this collision blocked the sunlight reaching the earth's surface and many forms of life became extinct due to the cold. fearing this threat, how large the radius of an asteroid should you be looking for if the dangerous asteroid size is approximately the same as the one that killed the dinosaurs? available data suggests that about 18% of that asteroid's mass ended up as a dust spread evenly over earth after eventually settling out of the upper atmosphere. about 0.0180 g/cm^2 of dust, which is chemically different than the earth's rock, covered the earth's surface. typical asteroids have a density of about 1.9 g/cm^3. now that we know the size of the asteroid, how much energy was released during impact, assuming all of it was just the kinetic energy of the asteroid right before the impact?

Eddy whose mass is 55kg climbs up the 1.50 meter high stairs in 2s. calculate eddy’s power rating