How much of a 1.0 g polonium-214 Sample remains after 818 microseconds ? The half life of polonium-214 is 163.7 microseconds

Asap 1. which surface feature of the moon is characterized by mountainous areas? question options: maria terrae regolith craters 2.which statement describes surface features called maria on the moon? question options: layers of dust and rock deep areas of cooled lava deep, rocky and barren valleys highlands and mountainous areas

Alead ball is dropped into a lake from a diving board 5m above the water . it hits the water with a certain velocity and then sink with constant velocity in bottom . it reaches the bottom 5 second after it is dropped if g= 10m/s2 . find depth of the lake and average velocity of the ball ?

If a simple machine reduces the strength of a force, what must be increased?