<span>With any element, there are a range of isotopes . . . a weighted average mass is used because there exist different isotopes of that element, each of varying mass. A weighted average accounts for the fact that the average mass (that may likely be measured from a random sample of the element) will most likely reflect the average mass of the more abundant isotopes. So the weighted average mass will be most comparable to the more abundant isotopes.</span>
Answer:
NaOH or sodium Hydroxide
Explanation:
The chief active ingredient in most over cleaners is NaOH or sodium hydroxide, also known as lye. Other common ingredients include butane (C4H10), Monoethanolamine (HOCH2CH2NH2) and Diethylene glycol monobutyl ether (C8H18O3).
Answer:
(<em>n</em> = 7) ⟶ (<em>n</em> = 4)
Explanation:
1. Convert the energy to <em>joules per mole of electrons</em>.
<em>E</em> = 55.1 × 1000 = 55 100 J/mol
2. Convert the energy to <em>joules per electron
</em>
<em>E</em> = 55 100/(6.022 × 10²³)
<em>E</em> = 9.150 × 10⁻²⁰ J/electron
3. Use the Rydberg equation to <em>calculate the transition
</em>
Rydberg's original formula was in terms of wavelengths, but we can rewrite it to have the units of energy. The formula then becomes
where
= the Rydberg constant = 2.178 × 10⁻¹⁸ J
and 
are the initial and final energy levels.
So potassium is more reactive than lithium because the outer electron of a potassium atom is further from its nucleus than the outer electron of a lithium atom. Hope this answers the question. Have a nice day. Feel free to ask more questions.
