If it has a positive charge it is a cation if negative it is an anion .
I attached a chart that will help you know the charges of the elements
Answer:
C. 11 moles of N2O
Explanation:
A. CO2 exists as a molecular compound. The number of atoms present = 1 atom of Carbon and 2 atoms oxygen = 3 atoms * 9 = 18 atoms
B. Xe exists as an atom. Number of atoms present = 10 * 1 atom = 10 atoms
C. N20 contains 3 atoms; 2 atoms of Nitrogen and 1 atom of oxygen.
Number of atoms present = 3 * 11 = 33 atoms
D. CO contains 2 atoms, 1 each of carbon and oxygen.
Number of atoms present = 12 * 2 = 24 atoms
Kia's remaining water has a mass of 50g. You can set it up as a proportion knowing that 100ml of water has a mass of 100g and thus 50ml of water would weight 50g
194.5 g of BCl₃ is present in 1 × 10²⁴ molecules of BCl₃.
Explanation:
In order to convert the given number of molecules of BCl₃ to grams, first we have to convert the molecules to moles.
It is known that 1 moles of any element has 6.022×10²³ molecules.
Then 1 molecule will have
moles.
So 
Thus, 1.66 moles are included in BCl₃.
Then in order to convert it from moles to grams, we have to multiply it with the molecular mass of the compound.
As it is known as 1 mole contains molecular mass of the compound.
As the molecular mass of BCl₃ will be

Mass of boron is 10.811 g and the mass of chlorine is 35.453 g.
Molar mass of BCl₃ = 10.811+(3×35.453)=117.17 g.


So, 194.5 g of BCl₃ is present in 1 × 10²⁴ molecules of BCl₃.
2 SO₃ --> 2 SO₂ + O₂
I 12 0 0
C -2x +2x +x
---------------------------------------------
E 12-2x 2x x
Since the moles of SO₂ at equilibrium is 3 mol, 2x = 3. Then, x = 1.5 mol. So, the amounts at equilibrium is:
SO₃: 12 - 2(1.5) = 9
SO₂: 2(1.5) = 3
O₂: 1.5
The formula for K basing on the stoichiometric reaction is:
K = [SO₂]²[O₂]/[SO₃]²
where the unit used is conc in mol/L.
K = [3 mol/3 L]²[1.5 mol/3 L]/[9 mol/3 L]²
<em>K = 0.0556</em>