The mineral magnesite contains magnesium carbonate, mgco3 (molar mass= 84 g/mol), and other impurities. when a 1.26-g sample of magnesite was dissolved in hydrochloric acid, 0.22 g of co2 was generated. if the magnesite contained no carbonate other than mgco3, what was the percent mgco3 by mass in the magnesite? the reaction is as follows:
mgco3(s) + 2hcl (aq) --> mgcl2(aq) + h20(l) + co2(g)

Two friends at different locations want to communicate with each other by sending low energy signals. which of the following methods can they use to communicate? a) produce x-rays using colliding electrons and send them to radios, which capture sound b) send messages using infrared radiation, which travel in the form of waves c) send radio waves through intervening media like radio and television d) produce sound waves using microwaves from heated objects

What problem would a person have if the nucleic acid in one of his or her cells were damaged?

Asample of aluminum foil contains 8.60 × 1023 atoms. what is the mass of the foil?