All categories

2 years ago

How is it possible for helium to have 8 spectral lines when it only has 2 electrons?

1 answer:

5 0

It has more lines in it compared to hydrogen emission spectrum. It is mainly because the helium atom has more electrons than a hydrogen atom. Therefore, more electrons get excited when we pass a white light beam through a helium sample, and it causes the emission of more spectral lines

You might be interested in

A compound die will be used to blank and punch a large washer out of aluminum alloy sheet stock 3.2 mm thick. the outside diamet

rodikova [14]

a) The sizes of punch and blanking are equivalent to its diameters. The blanking die diameter is Db = 65 mm

Diameter of the blanking punch is,

dpunch = Db - 2c

Here, c = Ac (thickness)

For aluminium, Ac = 0.06

c = (0.06) (3.2 mm) = 0.192 mm

dpunch = (65 mm) - 2 (0.192 mm)

= 64.616 mm

b) The diameter of the punching punch is equivalent to the interior diameter of the washer.

Thus, diameter of the punching die is, Dh = 30 mm

Diameter of the punching die is,

ddie = Dh + 2c

= (30 mm) + 2 (0.192)

= 30.384 mm

7 0

3 years ago

A 55.0 L sample of gas at 235 K exerts a pressure of 225 KPa. If its volume is decreased to 42.0 L and the temperature rises to

OleMash [197]

Answer:

Final pressure will be equal to 394.94 kPa

Explanation:

It is given volume $V_1=55L$

Temperature of the gas $T_1=235K$

Initial pressure exerted $P_1=225kPa$

Now volume is decreased to $V_2=42L$

And temperature is increases to $T_2=315K$

By using gas equation

$\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}$

$\frac{225\times 55}{235}=\frac{P_2\times 42}{315}$

$P_2=394.94kPa$

So final pressure will be equal to 394.94 kPa

4 0

2 years ago

Sodium only has one naturally occuring isotope, Na23 , with a relative atomic mass of 22.9898 u. A synthetic, radioactive isotop

NISA [10]

Answer:

0.000399316 g

Explanation:

We can start with the molar fraction for each isotope:

We can say that the abudandance of $^2^3Na$ is an unknow value "X" and the molar fraction of $^2^2Na$ is "Y". We have to keep in mind that the molar fractions can be added:

Y + X = 1

So, we can put the molar fraction of $^2^2Na$ in terms of $^2^3Na$ , so:

Y=1-X

So, we will have the molar fraction of each isotope:

$^2^2Na$ : X-1

$^2^3Na$ : X

And the atomic mass:

$^2^2Na$ : 21.9944

$^2^3Na$ : 22.9898

If we multiply the molar mass by the each atomic mass of each isotope we will have:

$22.9898*(X)~+~21.9944*(X-1)~=~22.9785$

Now we can solve for "X" :

$22.9898X~+~21.9944X~-21.9944~=~22.9785$

$44.9842X-21.9944~=~22.9785$

$44.9842X~=~22.9785~+~21.9944
$

$44.9842X~=~44.9729
$

$X~=~\frac{44.9729}{44.9842}$

$X~=~0.999749
$

The molar fraction of $^2^3Na$ is 0.999749. Now we can calculate the molar fraction of $^2^2Na$ , so:

$Y~=~1-0.999749~=~0.000251
$

Now, if we multiply the molar fraction by the mass we can find the mass of $^2^2Na$ , so:

$mass~of~^2^2Na~=~1.5909~g*0.000251~=~0.000399316~
g$

The mass of $^2^2Na$ is 0.000399316 g

I hope it helps!

4 0

3 years ago

Write the formula for an isotope of oxygen with nine neutrons, including the mass number and the atomic number. Write the answer

Mumz [18]

The formula for an isotope of oxygen with nine neutrons, including the mass number and the atomic number is 17/8 O.

<h3>What is an isotope?</h3>

Isotope is any of two or more forms of an element where the atoms have the same number of protons, but a different number of neutrons within their nuclei.

This means that atoms of isotopes will have the same atomic number but a different mass number.

According to this question, an isotope of oxygen has 9 neutrons. If oxygen has an atomic number of 8, the formula of this particular isotope is as follows: 17/8 O.

Learn more about isotopes at: brainly.com/question/12955625

#SPJ1

7 0

2 years ago

Please no links and round two decimal places

Juliette [100K]

Answer:

https://vm.tiktok.com/ZMet3FuC2/

8 0

2 years ago