17. Find the average atomic mass unit of silicon given the following isotopes and abundances: Silicon-28, Silicon-29, Silicon-30 with masses of 27.977, 28.976,
29.974, respectively. The percent abundance of the silicon isotopes is 92.2%, 4.7%
and 3.1%, respectively. Periodic table and it’s trends

The average atomic mass unit of Silicon : 28.0774

Given

Isotopes of Si(Silicon-28, Silicon-29, Silicon-30)

Required

The average atomic mass

Solution

Isotopes are elements that have the same Atomic Number (Proton)

Atomic mass is the average atomic mass of all its isotopes

Avg. atomic mass = %mass.isotopes 1 + %mass.isotopes 2...etc

Input the values :

Avg atomic mass = (0.922 x 27.977) + (0.047 x 28.976) + (0.031 x 29.974)

Avg atomic mass = 28.0774

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !

the answer is barium and copper bromide