The answer is 64.907 amu.
The atomic mass of an element is the average of the atomic masses of its isotopes. The relative abundance of isotopes must be taken into consideration, therefore:
atomic mass of copper = atomic mass of isotope 1 * abundance 1 + atomic mass of isotope 2 * abundance 2
We know:
atomic mass of copper = 63.546 amu
The atomic mass of isotope 1 is: 62.939 amu
The abundance of isotope 1 is: 69.17% = 0.6917
The atomic mass of isotope 1 is: x
The abundance of isotope 2: 100% - 69.17% = 30.83% = 0.3083
Thus:
63.546 amu = 62.939 amu * 0.6917 + x * 0.3083
63.546 <span>amu = 43.535 amu + 0.3083x
</span>⇒ 63.546 amu - 43.535 amu = 0.3083x
⇒ 20.011 amu = 0.3083x
⇒ x = 20.011 amu ÷ 0.3083 = 64.907 amu
Answer:
What do you mean what happened?
Explanation:
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Answer:
If there is 0.66 moles of iron(III)oxide produced, there reacte 0.99 moles of oxygen (O2)
Explanation:
Step 1: Data given
Number of moles iron (III) oxide (Fe2O3) = 0.66 moles
Step 2: The balanced equation
4Fe + 3O2 → 2Fe2O3
Step 3: Calculate moles of oxygen (O2)
For 4 moles Fe consumed, we need 3 moles of O2 to produce 2 moles of Fe2O3
For 0.66 moles Fe2O3 produced, we need 3/2 * 0.66 = 0.99 moles of O2
If there is 0.66 moles of iron(III)oxide produced, there reacte 0.99 moles of oxygen (O2)
Answer:
Explanation:
To convert from atoms to moles, we must Avogadro's number:
This number tells us the amount of particles (atoms, molecules, etc.) in 1 mole of a substance. In this case, it is atoms of magnesium in 1 mole.
- 6.022 *10²³ atoms Mg / 1 mol mg
Now, let's set up an expression using:
Multiply this by the given number of atoms.
Flip the fraction so the atoms of magnesium can cancel.
Multiply and condense this into 1 fraction.
The original measurement had 3 significant figures, so our answer must have that many as well. For the number we calculated, that is the tenth place. The 6 in the hundredth place tells us to round the 1 to a 2.
It is about <u>92.2 moles of magnesium.</u>
Answer:
2370.0 contains 4 significant digits and Option (c) is correct .
1.20\times 10^{-3}\ contains\ three\ significant\ digit.
Option (b) is correct .
Step-by-step explanation:
Rules for finding significant digit .
1 : Non-zero digits are always significant.
2: Any zeros between two significant digits are significant .
3: Trailing zeros in the decimal number is also significant.
As the number given be 2,370.0.
= \frac{23700}{10}
Simplify the above
= 2370
Thus by using the rule given above.
2370.0 contains 4 significant digits.
Option (c) is correct .
As the number given be 0.00120 .
= \frac{120}{100000}
Simplify the above
= \frac{1.20}{1000}
= 1.20\times 10^{-3}
Thus by using the rule given above.
1.20\times 10^{-3}\ contains\ three\ significant\ digit.
Option (b) is correct .
