Answer:
______is used in production of hard disk.
Explanation:
You would use this number, 6.02×1023 (Avogadro's number) to convert from particles, atoms, or molecules to moles. Whenever you go to the mole, divide by Avogadro's number. When you go to the unit from moles, multiply by Avogadro's number.
Answer:

Explanation:
Chemical Equations are representations of chemical reactions in terms of the symbols and formulae of the elements and compounds involved. A chemical equation usually have the reactant at the left hand side while the product is on the right hand side.
A chemical Equation is of little or no value if is not in balanced equation. When an equation is balanced , the total number of atoms of any element on the left-hand side of it must be equal to the total number of atoms of that element on the right hand side.
in the given question; we are given a word problem of chemical symbol to compute and also to balance the chemical equation.
From below; the chemical equation can be written as:

From the above equation we will notice that it is not truly balanced ; so th balanced equation can be written as:

Answer:
1. Dmitri Mendeleev
2. Johann Dobhereiner
3. John Newlands
4. Henry Moseley
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Mass of Oxygen: 0.0159 grams
Moles of Oxygen: 9.94x10^-4
To find the mass of oxygen, subtract the mass of copper from the total mass.

There are 0.0159 grams of Oxygen.
To find how many moles there are, divide the given amount of oxygen by the molar mass (atomic mass) of oxygen because that mass is the same as one mole of oxygen.
Molar mass of Oxygen: 16.00

There are 9.94*10^-4 moles of Oxygen.