Why do you think fossils are found in sedimentary rocks and not in igneous or metamorphic rocks?

Because igneous rocks are melted rock and metamorphic rocks have been under great pressure and are squashed or stretched and fossils wouldn't be able to survive these conditions.

Fossils are found in this rock because the rocks aren't formed from temperatures that would otherwise destroy them. Igneous rocks are formed by the cooling of lava, and metamorphic rocks are formed by another rock that undergoes extreme heat or pressure. Therefore, they both require heat, while sedimentary rocks are simply formed from deposed sediment from water.

Sorry i think the answer is b

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.