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.
Azeotropic mixture. I think
Answer:
The sharing of electrons between a water molecule that forms four hydrogen bonds with the other four water molecules:
Explanation:
The hydrogen bond is a weak electrostatic force of attraction that exists between a covalently bonded H-atom and a highly electronegative atom like N,O or F.
In the case of the water molecule,
the highly electronegative atom is Oxygen and the intermolecular hydrogen bond in water is as shown below:
Thus H-bond is a weak electrostatic attraction formed between H-atom and O-atom in water.
The reserve of a fossil fuel might be increased if mining or extraction techniques improve so that more of fuel can be extracted for a profit
