The half-life of radium is 1600 years. In what time will the mass of radioactive radon decrease by 4 times?

How many hydrogen (h) atoms are in one molecule of sulfuric acid, h2so4? (1 points) 1 2 4 7

Samir watches a 100-minute movie on his spaceship. maria's spaceshipe flies in the same direction as samir's spaceship but she observes his move to last 125 minutes and his spaceship to be 40 m long. how long does samir observe his own spaceship to be? according to an observer on earth, planet x is stationary. maria and samir depart earth on their spaceships at the same time, each flying at 0.5c. maria flies toward planet x and samir flies in the opposite direction. according to maria, her voyage to planet x takes 9 years. how many years does marias voyage take according to samir?

Can you match these to the correct definition