Answer:
In chemistry, a symbol is an abbreviation for a chemical element. Symbols for chemical elements normally consist of one or two letters from the Latin alphabet and are written with the first letter capitalised.
Earlier symbols for chemical elements stem from classical Latin and Greek vocabulary. For some elements, this is because the material was known in ancient times, while for others, the name is a more recent invention. For example, Pb is the symbol for lead (plumbum in Latin); Hg is the symbol for mercury (hydrargyrum in Greek); and He is the symbol for helium (a new Latin name) because helium was not known in ancient Roman times. Some symbols come from other sources, like W for tungsten (Wolfram in German) which was not known in Roman times.
Explanation:
15.63 mol. You need 15.63 mol HgO to produce 250.0 g O_2.
<em>Step 1</em>. Convert <em>grams of O_2 to moles of O_2</em>
Moles of O_2 = 250.0 g O_2 × (1 mol O_2/32.00 g O_2) = 7.8125 mol O_2
<em>Step 2</em>. Use the molar ratio of HgO:O_2 to convert <em>moles of O_2 to moles of HgO
</em>
Moles of HgO = 0.8885 mol O_2 × (2 mol HgO/1 mol O_2) = <em>15.63 mol HgO</em>
Answer:
223.6539
Explanation:
1 mole is equal to 1 moles KCl, or 74.5513 grams
The decreasing order of wavelengths of the photons emitted or absorbed by the H atom is : b → c → a → d
Rydberg's formula :
,
where λ is the wavelength of the photon emitted or absorbed from an H atom electron transition from 
to 
and 
= 109677 is the Rydberg Constant. Here and represents the transitions.
(a) =2 to = infinity
= 109677/4 [since 1/infinity = 0] Therefore, 
= 4 / 109677 = 0.00003647 m
(b) =4 to = 20
= 6580.62
Therefore, = 1 / 6580.62 = 0.000152 m
(c) =3 to = 10
= 11089.56
Therefore, = 1 / 11089.56 = 0.00009 m
(d) =2 to = 1
= - 82257.75
Therefore, = 1 /82257.75 = - 0.0000121 m
[Even though there is a negative sign, the magnitude is only considered because the sign denotes that energy is emitted.]
So the decreasing order of wavelength of the photon absorbed or emitted is b → c → a → d.
Learn more about the Rydberg's formula athttps://brainly.com/question/14649374
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Answer:
When cells become damaged or die the body makes new cells to replace them. This process is called cell division. One cell doubles by dividing into two. Two cells become four and so on.
Explanation:
