The right answer is 2.
The number of protons contained in a nucleus (called an atomic number) is characteristic of a chemical element. For a given atomic number, the number of neutrons defines different "types" of this element: isotopes. The variation of the number of protons of the nucleus of an atom, during a nuclear reaction for example, causes a change of the element studied.
The concentration of the original calcium ions is 0.005 M
<h3>What is concentration?</h3>
The term concentration has to do with the amount of substance in solution. We know that the concentration can be measured in a lot of units such as mole/litre, grams per litre, percentage and so on.
As such we have the equation;
Ca^2+(aq) + (NH4)2CrO4(aq) --------> CaCrO4(s) + 2NH4^+(aq)
Number of moles of the precipitate = 346.7 * 10^-3 g/156 g/mol
= 0.0022 moles
Now;
1 mole of Ca^2+ produces 1 mole of CaCrO4 hence 0.0022 moles of CaCrO4 was produced by 0.0022 moles of CaCrO4.
Given that the volume of the solution is 0.440 L, the concentration of the solution is; 0.0022 moles/0.440 L
= 0.005 M
Learn more about molarity:brainly.com/question/8732513
#SPJ1
The mass fraction of sodium chloride is 0.0625
<h3>What is the mass fraction of sodium chloride in the solution?</h3>
The mass fraction of sodium chloride is the ratio of the mass of sodium chloride to the total mass of the solution.
The mass fraction of sodium chloride is determined as follows;
mass of sodium chloride = 20 g
- mass of water = volume * density
density of water = 1 g/mL
volume of water = 300 mL
mass of water = 300 mL * 1 g/mL
mass of water = 300 g
total mass of solution = 20 + 300 = 320 g
mass fraction of sodium chloride = 20/320
mass fraction of sodium chloride = 0.0625
Learn more about mass fraction at: brainly.com/question/14783710
#SPJ1
Answer:
covalent
Explanation:
C2S6 is a compound made of 2 nonmetals which makes it covalent
Hope this helps! Plz mark brainliest
