Metal vapor deposition is a process used to deposit a very thin layer of metal on a target substrate. A researcher puts a glass slide in the metal vapor deposition chamber and coats the slide with copper. After deposition, the glass slide had increased in mass by 2.26 milligrams. Approximately how many copper atoms were deposited on the glass slide

2.14x10¹⁹ atoms of Cu were deposited

Explanation:

The increased in mass of the glass slide is due the deposition of copper.

That means the mass of copper deposited is 2.26mg = 2.26x10⁻³g Cu

To know the copper atoms we need to convert this mass to moles of Cu using molar mass of copper (63.546g/mol), and these moles are converted to atoms using Avogadro's number (6.022x10²³ atoms = 1 mole)

Moles Cu:

2.26x10⁻³g Cu * (1 mol / 63.546g) = 3.556x10⁻⁵ moles Cu

Atoms Cu:

3.556x10⁻⁵ moles Cu * (6.022x10²³ atoms / 1 mole) =

2.14x10¹⁹ atoms of Cu were deposited

answer; protein;

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 !