Which two minerals are softer than a human finger nail 1)calcite and halite 2)sulfer and fluoriye 3)graphite and talc 4)pyrite and magnetlite

An example of technology is the a. addition of a side group to an organic molecule during synthesis. b. use of a new antibiotic to fight an infection. c. measurement of iron concentration in a water sample. d. study of atomic fusion reactions

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.

Design techniques and materials that reduce the negative environmental impact of a structure are referred to as