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4 years ago

How many electrons does 0^2- have ? Please explain how that is the answer

Chemistry

1 answer:

MAXImum [283]4 years ago

8 0

An oxygen atom with a charge of negative two, written as 2- , would have 10 electrons

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The half-life of a positron is very short. It reacts with an electron, and the masses of both are converted to two gamma-ray pho

sp2606 [1]

Explanation:

(a) It is known that relation between energy and mass is as follows.

$E = 2 \times mc^{2}$

where, E = energy

m = mass

c = speed of light = $3 \times 10^{8}$ m/s

As it is given that mass is $9.109 \times 10^{-31}$ kg. So, putting the given values into the above formula as follows.

$E = 2 \times mc^{2}$

= $2 \times 9.109 \times 10^{-31} kg \times 3 \times 10^{8}m/s$

= $1.638 \times 10^{-13} J$

Therefore, we can conclude that the energy produced by the reaction between one electron and one positron is $1.638 \times 10^{-13} J$ .

(b) When gamma ray photons are produced then they will have the same frequency. Relation between energy and frequency is as follows.

E = $h \times \nu$ ..... (1)

where, h = plank's constant = $6.626 \times 10^{-34} J.s$

$\nu$ = frequency

Also, $E = 2 \times mc^{2}$ ........ (2)

Hence, equating equations (1) and (2) as follows.

$h \times \nu$ = $2 \times mc^{2}$

So,

$6.626 \times 10^{-34} Js \times \nu$ = $1.638 \times 10^{-13} J$

$\nu$ = $1.236 \times 10^{20} Hz$

Thus, we can conclude that the frequency is $1.236 \times 10^{20} Hz$ .

5 0

4 years ago

What are stars in our solar system

Cloud [144]

The stars in the solar system are made of hydrogen and helium

6 0

3 years ago

A vessel is full of a mixture of kerosene and petrol in which there is 18% kerosene.Eight litres are drawn off and then the vess

ExtremeBDS [4]

The answer in here is d)48 lit. We know this when we do the following procedure:
<span>kerosene=18%
so petrol =82%
after kerosene =15%
petrol=85%
so 3% =8
lit so total kerosene in the mixture =(8x18/3) =48 lit
</span>Hope this is useful

6 0

3 years ago

If 0.62 moles of KClO3 is decomposed, how many grams of O2 are produced?<br><br> 2KClO3 → 2KCl + 3O2

kotegsom [21]

Answer: 9.79 g of oxygen is produced.

6 0

2 years ago

Read 2 more answers

EXTREME HURRY!! State the ionization constant expression Ka for lactic acid. Given: pKa = 3.85 and Ka = 1.4*10^-4 mol dm^-3

Eduardwww [97]

Ka expression for any substance:
Ka = [H+] [A-] / [HA]

In this case,
Ka = [H+][C₃H₅O₃-]/[C₃H₆O₃]
1.4 x 10⁻⁴ = [H+] [C₃H₅O₃-] / [C₃H₆O₃]

pKa = -log(Ka)
pH = -log([H+])
The difference between pKa and pH is that pH is the negative logarithm of only the concentration of hydrogen ions, while pKa is the negative logarithm of the ratio of the product of the concentrations of hydrogen ions and concentration of base to the concentration of acid.

5 0

4 years ago