Answer:
A
Explanation:
I guess it's a, because nuclear decay is likely to occur when either the mass or atomic number is greater than 83.
Hey there!:
Number of moles:
Molar Mass Al = 26.98 g/mol
n = mass / molar mass
n = 9.0 / 26.98
n = 0.3336 moles of Al
Given the reaction :
2 Al + Fe2O3 = Al2O3 + 2 Fe
From the equation, 2 moles of Al give off 849 kJ of heat :
Actual heat given off :
0.3336 / 2 * 849 =
0.3336 / 1698 = 1.4*10² Kj
Hope that helps!
To balance the the chemical reaction, the number of moles
per element is balance is both side of the reaction and also the charge in both
sides of the reation. to balnce the reaction:
S2O3 2- + Cu 2+ ---> S4O6 2- + Cu+
2S2O3 2- + Cu 2+ ---> S4O6 2- + Cu+ + e
<span><span>There is no formula. The speed of light is a fundamental constant which appears in other formulas but there’s no formula to compute the numerical value.Well, actually, that’s not quite right. The numerical value in meters per second is known exactly, because we use the speed of light to define the meter. It is: <span><span><span>c=299,792,458 m/s</span><span>c=299,792,458 m/s</span></span>
</span>. Exactly. But the thing is — this value is purely an artifact of our unit system. Other unit systems will give other values, so the number value is entirely arbitrary.</span></span>
