Nitrogen makes up around 78% of the total atmosphere.
Beryllium is a chemical element with symbol Be and atomic number 4. It is a relatively rare element in the universe, usually occurring as a product of the spallation of larger atomic nuclei that have collided with cosmic rays.
Answer #1 is "there is 2.5 grams of solute in every 100 g of solution."
We calculate for 2.5% by mass solution by dividing the mass of the solute by the mass of the solution and then multiply by 100.
Answer #2 is "that mass ratio would be 2.5/100 or 2.5 grams of solute/100 grams of solution."
We weigh out 2.5 grams of solute and then add 97.5 grams of solvent to make a total of 100 gram solution, that is,
mass of solute / mass of solution = 2.5g solute / (2.5g solute + 97.5g solvent)
= 2.5g solute / 100g solution
Answer#3 is "a solution mass of 1 kg is 10 times greater than 100 g, thus one kilogram (1 kg) of a 2.5% ki solution would contain 25 grams of ki."
We multiply 10 to each mass so that 100 grams becomes 1000grams since 1000 grams is equal to 1 kg:
mass of solute / mass of solution = 2.5g*10/[(2.5g*10) + (97.5g*10)]
= 25g solute/(25g solute + 975g solvent)
= 25g solute/1000g solution
= 25g solute/1kg solution
<span>Cations mix with anions, so you know NH4+ won't mix with K+ and SO4(2-) won't miix with F-. For the reason that NH4+ and F- together have single charges, they'll mix in a 1:1 ratio, NH4F. There's two charges on SO4(2-), so it'll need two K+ to mix with, K2SO4.</span>
Atomic number refers to the proton number of the atom itself. Number of electrons in an atom (an atom that is not reacted with any other molecules / Just the atom alone), is the same as the number of protons, because each electron has 1 negative charge, and each proton 1 positive charge, where they cancel out on each other to become a neutral charge.
So, when atomic number is 6, proton number is also 6, and number of electrons will also be 6 in that atom.
Hope this helps! :)