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.
Vertical columns are called groups, or families.
They share similar chemical properties.
Answer: <span>have similar chemical properties</span>
<span>it is A. Mendeleev observed that tellurium has chemical....</span>
Answer:
(1) Bromination, (2) E2 elimination and (3) epoxidation
Explanation:
- In the first step, -OH group in cyclopentanol is replaced by more facile leaving group Br by treating cyclopentanol with

- In the second step, E2 elimination in presence of strong base e.g. NaOEt/EtOH produce cyclopentene
- In the third step, treatment of cyclopentene with mCPBA produces 1,2-epoxycyclopentane
- Full reaction scheme has been shown below