Bài 1. Tính khối lượng(m) của: a) 0.4 mol nguyên tử nhôm a1) 1,125 mol thuốc tím KMnO4
b) 0,125 mol sắt b1) 0,2 mol chì
c) 0,1 mol Khí oxi c1) 0,15 mol BaSO4
d) 0,5 mol Cl2 d1) 0,25 mol Al(OH)3
e) 0,75 mol khí nito e1) 0,45 mol Mg(NO3)2
f) 1,15 mol kẽm f1) 1,5 mol muối ăn NaCl

(Al=27, Fe=56, Pb=207, O=16, Ba=137, S=32, Cl=35,5 N=14,
Mg=24, Zn=65, Na=23, K=39, Mn=55)

The answer is c - the principal of original lateral continuity. 

I’m not sure about this question

Ithink about 50 % of an original isotope's number of atoms remain

1. why does the same side of the moon always face earthc.the rotational period of the moon is equal to one revolution around earth2. which is greater the moons period of rotation or its period of revolution  b.the moons revolution period around earth3.what was the major accomplishment of the apollo missions  c.sending the first human into space4. which of these space missions involved the deployment of lunar roversa. voyager 15. which scientists are going to explore next on kepler-186fd. evidence of existence of life6.which mission is not going to explore the outside of the solar  systemb.safir7.which technology limit the future of space explorationb. scientist must first develop certain technologies before missions can be completed.