When you change the number of protons in an atom, you will change the atom from one element to a different element. Sometimes, when you add a proton to an element, the element will become radioactive. If you change the number of electrons in an atom, you will get an ion of the element.
Answer:
fe(iron) + cl^2 (clorine) = fecl^3(iron cloride)
Answer:
Disnt make sense show me question
8. A. Density is independent of size (an intensive property).
9. B. The highest density is 1786 g/20cm^3, or 89.3 g/cm^3. The least is 512 g/20cm^3, or 25.6 g/cm^3. Therefore, the difference is 89.3 - 25.6, or 63.7 g/cm^3.
10. C. A bottle filled with air weighs less than one filled with marshmallows, because air is less dense than marshmallows.
11. D. The number represents the number of protons in the nucleus of the atom, as well as the atomic number of the element.
12. C. The number represents the atomic mass of the element, which is determined based on the relative abundance of each form of the element.
Answer : The mass of 
is, 4.43 grams.
Explanation :
As we know that, when dissolve in water then it dissociates to give 2 mole of sodium ion 
and 1 mole of sulfate ion 
The chemical reaction will be:
Thus, the concentration of = 
First we have to calculate the moles of
Now we have to calculate the mass of
Molar mass of = 142 g/mol
Thus, the mass of is, 4.43 grams.
