1. The compound 2NaCl consists of A.2 atoms of sodium element B. 1 atom of chlorine element C. 3 atoms of sodium element D. 1 atom of sodium element
2. The valency of iron in iron (III) sulphate is A.3 B.2
C.4
D.5
3.The systematic name of the compound Cuso, is A. Copper (I) sulphate B. Copper
(II) tetraoxosulphate C. Copper (II) tetraoxosulphate (IV) D. Copper (II)
tetraoxosulphate (VI)​

Ithinks its false. tell me if im wrong

Density and pressure

There is no reason to think the results are biased or not conducted properly but you should not assume the results are correct just because they were done in a laboratory so the answer would be c. it is likely to be reliable because the results support the conclusion presented.

Answer : option a) 84explanation :

considering the question as per the attachment

here we can see that the radon nuclide has 222 as the atomic mass number and 86 as the atomic number.

when it undergoes nuclear fission it gives polonium which has atomic mass number as 218 and atomic number will be 84 along with a helium nucleus which has 4 atomic mass number and 2 as its atomic number.

222 = 218 + 4 (atomic mass number)

86 = ? + 2; therefore ? = 86-2 = 84.

the atomic mass number of polonium will be 84.