35-18 = 17 protons = <u>17 electrons</u>
Start by adding ten to 90 then subtract ING one
Answer:
41.4%
Explanation:
The salt copper II fluoride tetrahydrate is a hydrated salt. A hydrated salt is a salt that has some molecules of water of crystalization attached to its structure. The formula of the salt is CuF2.4H2O
The first step is to calculate the molecular mass of the compound as follows
[64 + 2(19) + 4((2×1) + 16)] = [64 + 38 + 72]= 174gmol-1
Mass of water of crystallization= 4((2×1) + 16) = 72 g
Percentage by mass of water of crystallization= 72 / 174 ×100
Percentage by mass of water if crystalization = 41.4%
Answer:
1.81 x 10²⁴atoms
Explanation:
Given parameters:
Number of molecules = 3 moles
Unknown:
Number of atoms = ?
Solution:
To solve this problem, we are going to use the mole concept.
1 mole of any substance contains 6.02 x 10²³ atoms
So
3 mole of propanone will contain 3 x 6.02 x 10²³ atoms = 1.81 x 10²⁴atoms
