What are two elements scientists should investigate, which could substitute for two of the five other elements (O, C, H, N, S) we know to be essential for life?

a. Si, Na
b. SK
c. As, Si
d. S,F

Which produce would best increase the amount of heat energy that is actually gained by calorimeter b

What stress will shift the following equilibrium system to the left? n2(g) + 3h2(g) ⇌ 2nh3(g) adding more n2(g) adding more nh3(g) increasing the pressure of the system reducing the volume of the container

Achemist 16 drop copper metal from copper chloride solution. the chemist place is 0.50 g of aluminum foil in a solution containing 0.75 g of copper (ii) chloride. a single replacement reaction takes place. which statement explains the maximum amount of copper that the chemist can extract using this reaction?