Answer:
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Explanation:
Answer:
In hyphen notation, the mass number is written after the name of the element. For example, in isotopic notation, the isotope of carbon that has a mass number of twelve would be represented as 12C . In hyphen notation, it would be written as carbon-12.
Explanation:
lol just took the question and looked it up online this was the first thing that i saw if its not correct im sorry
<span>12.4 g
First, calculate the molar masses by looking up the atomic weights of all involved elements.
Atomic weight manganese = 54.938044
Atomic weight oxygen = 15.999
Atomic weight aluminium = 26.981539
Molar mass MnO2 = 54.938044 + 2 * 15.999 = 86.936044 g/mol
Now determine the number of moles of MnO2 we have
30.0 g / 86.936044 g/mol = 0.345081265 mol
Looking at the balanced equation
3MnO2+4Al→3Mn+2Al2O3
it's obvious that for every 3 moles of MnO2, it takes 4 moles of Al. So
0.345081265 mol / 3 * 4 = 0.460108353 mol
So we need 0.460108353 moles of Al to perform the reaction. Now multiply by the atomic weight of aluminum.
0.460108353 mol * 26.981539 g/mol = 12.41443146 g
Finally, round to 3 significant figures, giving 12.4 g</span>
Answer:
Explanation:
Your nuclear equation is
The main point to remember in balancing nuclear equations is that
- the sum of the superscripts and must be the same on each side of the equation.
- the sum of the subscripts must be the same on each side of the equation.
Then
85 = 0 + y, so y = 85 - 0 = 0
35 = -1 + x, so x = 35 + 1 = 36
The nucleus with atomic number 36 and atomic mass 85 is krypton-85.
The nuclear equation becomes
