Cobalt-59 and Cobalt-60 differ in that they have different mass number which means they have different number of neutrons. Isotopes are atoms of the same element with similar atomic number but different mass number. Cobalt-60, has a number of uses, which includes, being used to irradiate food sources as a method of preserving food, used in industrial radiography to detect structural flaws in metal parts among other uses.
Answer:
The calculated density will be larger
Explanation:
The calculated density will be <u>larger</u>. Because, the volume is taken accurately, by the water displacement method. But, when we the took the mass, the water was present on the unknown solid. So, the mass of that water was added to the original mass of the solid. Hence, the mass measured was larger than the original mass. We, know from the formula of density that density is directly proportional to the mass of the object.
Density = Mass/Volume
Hence, the larger measured mass means the larger value of density.
Isotopes are basically from the same element. In terms of subatomic particles of the element, the isotopes will then basically have the same number of protons. The electrons also have to be same in number given that the elements are in neutral charges.
We are then left with neutrons, which is one of the subatomic particles residing in the nucleus of an atom.
Thus, the answer is NEUTRONS.
<span>1. What is the molar mass of gold?
Molar mass is a unit that expresses the mass of a molecule per one mol. The molar mass can be obtained by adding the neutron with the proton of the atoms. Gold has atomic number 79 so the proton is 79. The number of the neutron is 118. Then the molar mass would be: 79 + 118 = </span>197 g/mol<span>
</span><span>2. Calculate the number of moles of gold (Au) in the sample. Show your work.
</span>In this question, you are given the mass of the gold and asked for how many moles the sample has. To find the number of moles you just need to divide the weight by the molar mass.
For 45.39 grams of gold, the number of moles would be:
45.39 / (197g/mol)= 0.23 moles
3. Calculate the number of atoms of gold (Au) in the sample. Show your work.Moles is unit of a number of molecules but 1 mol doesn't represent 1 molecule. The number of atoms can be obtained by multiplying the number of moles with Avogadro number. The calculation would be:
0.23 moles * (6.023 * 10^23 molecules/mol)= 1.387 * 10^23 molecules
