Answer:
The number of protons is equal to the mass number of the element. Since an element always has a different number of protons, the mass can indicate how many neutrons are in an isotope. Atoms of the same element can have a different number of neutrons. There are three naturally-occurring isotopes of carbon.
Explanation:
Atomic mass of helium is 4.002642g/mol
(542000g)/(4.002642g/mol)*6.02*10^23 = 8.15*10^28 atoms
Arsenic, I believe. Metalloids fall in between metals and nonmetals (usually on the bold line separating the two on the periodic table). And since the metalloid in question has four electron shells and five valence electrons in the outermost shell, you can see that this element is arsenic
Answer:
solubility of X in water at 17.0
is 0.11 g/mL.
Explanation:
Yes, the solubility of X in water at 17.0
can be calculated using the information given.
Let's assume solubility of X in water at 17.0
is y g/mL
The geochemist ultimately got 3.96 g of crystals of X after evaporating the diluted solution made by diluting the 36.0 mL of stock solution.
So, solubility of X in 1 mL of water = y g
Hence, solubility of X in 36.0 mL of water = 36y g
So, 36y = 3.96
or, y =
= 0.11
Hence solubility of X in water at 17.0
is 0.11 g/mL.