Which one of the following samples has the greatest mass?
a.
4.6 mol of iodine vapor, i2
b.
4.1 mol of ammonia, nh3
c.
0.39 mol of camphor, c10h16o
d.
1.8 mol of formaldehyde, ch2o
e.
9.2 mol of krypton, kr

Go to your periodic table and look up the elements and add up for the compounds.

I = 127, Kr = 84, NH₃ = 17, C₁₀H₁₆O = 152, CH₂O = 30

A)
I₂ = 2* I = 2*127 g/mol = 254 g/mol,  4.6 mol = 4.6 * 254 = 1168.4 g

B) 4.1 mol of NH₃ = 4.1 * 17 = 69.7

C) 0.39 mol of C₁₀H₁₆O = 0.39 * 152 = 59.28g

D) 1.8 mol of CH₂O  = 1.8*30 = 54g

E) 9.2 mol of Kr = 9.2 * 84 = 772.8g

The largest as you can see is A.

A.  4.6 mol of iodine vapor, I₂

The answer is b metal denting

Yes it would be a physical change.