Ineed an answer asap

which of the following is a chemical change?
question 4 options:

ice melting

glass breaking

sugar dissolving

nails rusting

Nails rusting

Explanation:

The rest of them still have the same chemical composition such as melting ice will still have a H2O chemical composition.

i think the answer is terrae but not 100 percent sure. ▓▬▬ §

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.