There isn't really a specific number of isotopes that elements have to have. But the isotopes are determined by the average mass of the element found in nature. And elements have varying masses because neutrons) leave and enter the atom. (neutrons are big enough that leaving the atom cause a difference in mass but electrons leaving will not, since they are so small)
Answer 16. True 17. True 18. False 19. True 20. False
Gas, as the particles have the most energy, and thus move the most.
Answer:
1.5 mol H2O
Explanation:
2C2H6 + 7O2 -> 4CO2 + 6H2O
The limiting reactant is C2H6
30 g C2H6 ->1 mol C2H6
15 g C2H6 -> x x= 0.5 mol C2H6
2 mol C2H6 -> 6 mol H2O
0.5 mol c2H6 -> x x = 1.5 mol H2O
The question is incomplete, the complete question is;
A magnet was placed near a pile that contained both iron and sulfur. The magnet was moved gradually closer to the pile. As it neared the pile, the magnet started attracting small pieces of iron from the pile. Which of these statements best describes the contents of the pile?
F. It is a homogeneous mixture of iron and sulfur. G. It is a heterogeneous mixture of iron and sulfur. H. It is a compound that contains both iron and sulfur. I. It is a compound that can be separated by magnetism.
Answer:
G. It is a heterogeneous mixture of iron and sulfur.
Explanation:
A heterogeneous mixture is one that does not have a uniform composition throughout.
We must recall that a mixture is any combination of substances that do not chemically react together and are separable by physical means.
Having said this, it is clear that I can separate the iron from sulphur by simple magnetic (physical) means. Hence, it is a heterogeneous mixture of iron and sulfur.
