Answer: 2.88×
atoms 
Explanation: First, using stoichiometry, we must convert this from grams to moles, then from moles to atoms.
1. For the first step, we should also look at the periodic table to find the molar mass of the compound, then use that as the denominator.

2. Now that it is converted to moles, we must convert it to atoms by multiplying it by Avogadro's number.

With this information, we know that there are
total atoms in 0.680 grams
.
I hope this helps! Pls give brainliest!! :)
When you see a long dash joining two elements in the structural formula of a chemical molecule you can assume that the chemical bonds in the compound are simple bonds.
In the representation of chemical molecules long dashes are used to represent simple bonds since these bonds are longer than double and triple bonds, which are represented by = and ≡ respectively.
Assuming the complete question is;
Consider the balanced equation below;
4NH3 + 3O2 = 2N2 +6H2O
What is the mole ratio of NH3 to N2;
From the balanced equation; the mole ratio of NH3 to N2 is 4:2.
The mole ratio is the ratio of moles of one substance to the number of moles of another substance in a balanced equation. In the above equation; 4 moles of ammonia requires 3 moles of oxygen to produce two moles of nitrogen and six moles of water.
1) State the balanced chemical equation
Na3 PO4 + 3 AgNO3 → 3NaNO3 + Ag3 PO4
sodium phosphate silver nitrate sodium nitrate silver phosphate
2) State the molar ratios
1 mol Na3PO4 : 3 mol AgNO3 : 3 mol NaNO3 : 1 mol Ag3 PO4
3) As you see 3 moles of Silver Nitrate react with 1 mol of Na3 PO4, then you will need.
The you need to use the molar ratio 1:3 to calculate the number of moles of sodium phosphate
1 mol Ag NO3 * [ 1 mol Na3 PO4 / 3 mol Ag NO3] = 0.33 mol Na3 PO4
Answer: 0.33 mol sodium phosphate
The electron configuration of the element in period 3, group 6A is [Ne]3s-2 3p-4.