<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>
Answer:
<u>When small organic molecules bind together, they form larger molecules called biological macromolecules.</u>Biological macromolecules are important cellular components and perform a wide array of functions necessary for the survival and growth of living organisms. The four major classes of biological macromolecules are carbohydrates, lipids, proteins, and nucleic acids.
(i hope this helps)
Answer:
Ag
Explanation:
To determine which element will displace hydrogen from a dilute acid, we need to make reference to the activity series or the electrochemical series. The activity series is a list of metallic ions according to their electropositivity.
This means elements are ranked here based on how electrically positive they are. Hence, an element above another element is relatively more electropositive than the one under it. For example calcium is less electropositive compared to sodium as calcium is found under sodium in the list.
Now, for an element to displace hydrogen, it means the particular element is more electropositive than hydrogen on the activity series. All the elements in the options are in a greater position relative to hydrogen on the activity series except silver. This means it cannot displace hydrogen from a dilute mineral acid
Answer:
Option C is the correct. Valence electrons have a higher energy level than those in other filled shells
Explanation:
Electrons must lose energy to move from the first to the second shell. FALSE
The electrons always win energy to move from the first to the second shell.
All the electrons in an atom have similar energy levels FALSE.
They are not neccesary similar. In hydrogen these are the level energy -13.6 eV
, -3.4 eV
, -1.51 eV
, -85 eV and -54 eV
Electrons do not have potential energy, just kinetic energy. FALSE
They have both.
Valencia electrons are the last electrons in the last layer. They have as much energy as possible and are responsible for forming bonds with other elements.
Answer:
Tyrosine is a polar and aromatic compound. its side chain acidity and basicity is neutral
if a peptide contain only a string of tyrosine residue especially l tyrosine the solubility increases more
Explanation:
even tyrosine number remains constant, tyrosine containing peptide will be more soluble. This peptide is soluble in 1 M HCl (100 mg/ml), with heating. The solubility in water (25 °C) is 0.45 mg/ml in the pH range 3.2 - 7.5.
2.0 mg/ml; at pH 9.5, the solubility is 1.4 mg/ml; and at pH 10, the solubility is 3.8 mg/ml.
