How many grams do 1.5 x 1026 atoms of magnesium weigh?

What is the percentage by mass of silicon (si) in iron aluminum silicate (fe3al2(sio4)3)?

Which of these is not an example of chemical weathering? a. iron-rich mineral rusting b. feldspar turning into clay c. limestone reacting with acid d. granite breaking up into sand

What type of chemical reaction occurs between silver nitrate (agno3) and copper (cu)? the equation i was given is 2agno3 + cu —> 2ag+ cu(no3)2.