The heat required to completely melt the given substance, platinum, we just have to convert first the given mass in mole and multiply the answer to its molar heat of fusion..
Hf = mass x (1/molar mass) x molar heat of fusion
Hf = (85.5 g) x (1 mole/195.08 g) x 4.70 kcal/mol
Hf = 2.06 kcal
Im just guessing, so i think is A
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.
Its molecule contains one oxygen and two hydrogen atoms.
Explanation:
Water is a chemical substance with the chemical formula H2O. Water is a chemical substance with the chemical formula H2O. Its molecule contains one oxygen and two hydrogen atoms connected by covalent bonds.
Hope this helps ; )
The molecules remain intact.