A sample of fluorine-18 in a laboratory has an initial mass of 50mg. flourine-18 has a half life of 1.8 hours Calculate the amount of time it will take for the initial mass of fluorine-18 to be reduced from 59 mg to 12.5mg

1. What is the speed of sound in air that has a temperature of 90.0 °C?

What is the velocity of a dropped object after it has fallen for 3.0 seconds?

What are three characteristic properties of matter?

What THREE properties determine the speed at which a sound wave travels in a medium?

If the horizontal component of a vector is 6 m/s and the vertical component is also 6 m/s, what is the resultant value of the vector? A. 6 m/s B. 8.5 m/s C. 10.4 m/s D. 12 m/s

F an electron fell to a lower orbit or energy level, energy would be A. created. B. emitted. C. absorbed. D. transferred.

Which is the correct order from the closest to the sun to the farthest away from the sun? A. terrestrial planets, asteroid belt, gas planets, Kuiper belt B. gas planets, asteroid belt, terrestrial planets, Kuiper belt C.

Ethylene (C2H4) reacts with oxygen gas to produce carbon dioxide and water. 45.0 grams of ethylene reacts, how many grams of carbon dioxide gas will be produced?

What causes ice to melt and water to boil

A block of mass 3.5 kg slides down a frictionless inclined plane of length 6.4 m that makes an angle of 30 degrees with the horizontal. if the block is released from rest at the top of the incline, what is its speed at the bottom