a meteorite was found to contain 40 argon-40 atoms for every 10 potassium-40 atoms. the half-life of potassium -40 atoms the half-life of potassium-40 is 1.25 billion years. assuming no loss of daugther isotopes how old is the moon rock

Total solidification times of three casting geometries are to be compared: a sphere, a cylinder, in which the length-to-diameter ration - 1.0, and a cube. volume = 1000 cm^3 for all three shhapes, and the same casting alloy is used. a) determine the solidification times of each geometry b) based on the results of part (a), which geometric element would make the best riser? c) if the mold constant = 3.5 min/cm^2 in chvorinov's rule, compute the total solidification time for each casting.

What are known as the properties of substances that describe a substance et does not change that substances?

Carbon tetrachloride (ccl4) is ionic or convalent