Must contain: 6 protons, 6 electrons and 12 neutrons.
Answer:
Evaporation
Explanation:
Heat makes molecules move and eventually evaporate.
Answer:
B) All carbon atoms have 6 neutrons.
Explanation:
The false statement from the given choices is that all carbon atoms have 6 neutrons.
There is a phenomenon called isotopy in chemistry.
Isotopy is the existence of two or more atoms of the same element having the same atomic number but different mass numbers due to the differences in the number of neutrons in their various nuclei.
- These atoms of elements are called isotopes.
- Carbon atoms generally have proton number of 6 which is the same as the atomic number.
- As with all atoms, the mass number or atomic mass equals the number of protons and neutrons.
For the isotopes of carbon, their number of neutrons differs.
For example:
<em>¹²₆C ¹³₆C ¹⁴₆C</em>
The number of neutrons differs in the above isotopes.
Number of neutrons = mass number - atomic number;
¹²₆C , number of neutrons = 12 - 6 = 6
¹³₆C, number of neutrons = 13 - 6 = 7
¹⁴₆C, number of neutrons = 14 - 6 = 8
Therefore, based on the concept of isotopy, all carbon atoms do not have 6 neutrons.
<span>Well it depends on percentage by what, but I'll just assume that it's percentage by mass.
For this, we look at the atomic masses of the elements present in the compound.
Cu has an atomic mass of 63.546 amu
Fe has 55.845 amu
and S has 36.065 amu
Since there are 2 molecules of Sulfur for each one of Cu and Fe, we'll multiply the Sulfur atomic weight by 2 to obtain 72.13 amu
So we have not established the mass of the compound in amus
63.546 + 55.845 + 72.13 = 191.521
That is the atomic mass of Chalcopyrite. and Iron's atomic mass is 55.845
So to get the percentage, or fraction of iron, we take 55.845 / 191.521
Which comes out to 29.15% by mass
Mass of the sample is not needed for this calculation, but since the question mentions it I would go ahead and check if the question isn't also asking for the mass of Iron in the sample as well, in which case you just find the 29.15% of 67.7g</span>
