Answer:
A machine have 75% efficiency means 25% of efficiency has been lost due to friction and a machine can work 75% only.
<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>
<span>Precipitation is the answer. i Hope i helped :3</span>
The parent isotope is cobalt-59 (see the picture below).
The mass number is 59 and atomic number is 27 of the parent isotope.
Neutron activation is the process in which atomic nucleus capture free neutron or neutrons.
Cobalt-60 is produced in nuclear reactors in process of neutron activation from parent isotope cobalt-59 (see the picture below).
Atomic number (Z) is total number of protons and mass number (A) is total number of protons and neutrons in a nucleus.
Cobalt-59 and cobalt-60 are the isotopes of chemical element cobalt.
Isotopes are chemical elements with same atomic number (Z), but different mass number (different number of neutrons).
More about isotopes: brainly.com/question/364529
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