15. How many moles of electrons is required to deposit 5.6g of iorn from a solution of iron (II) tetraoxosullphate (VI)? [Fe = 56, S = 32, 0 = 16] (a) 0.1 moles (b) 0.2 moles (c) 1.0 moles (d) 2.0 moles.​

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.