I believe it would be Au^4Cl8
Using the law of dilution :
Mi x Vi = Mf x Vf
2.00 x Vi = 0.15 x 100.0
2.00 x Vi = 15
Vi = 15 / 2.00
Vi = 7.5 mL
hope this helps!
I would think it is a heterogeneous mixture since it can't be an element since there are more than one type of atom, it can't be a compound since the leaves are not bonded together, and it can not be a homogeneous mixture since the leaves don't all blended together (the pile is not uniform) and you can distinguish all the different parts of the mixture. It can be considered a heterogeneous mixture since the leaves are mixed together (along with other things like dirt) in a non-uniform way so that you can point out the parts of the mixture and it does not look like one thing.
I hope this helps. Let me know in the comments if anything is unclear.
The atomic number of an element never changes no matter how many neutrons they have so Sulfur would just have an atomic number of 16 like normal.
