How many grams of Be are there in a sample of Be that contains the same number of moles as a 67.0 gram sample of Ca? grams of Be

Atank contains 240 liters of fluid in which 10 grams of salt is dissolved. brine containing 1 gram of salt per liter is then pumped into the tank at a rate of 6 l/min; the well-mixed solution is pumped out at the same rate. find the number a(t) of grams of salt in the tank at time t.

Which metal exist in liquid state and can be cut with knife ?

All forces cause motion? true or false