Question

$\sf{\underline{\large{Bonjour\:les\:amis!}}}$
1. The mass of hydrogen is 1 and atomic number is 1. What will be the atomic structure of hydrogen?

2. The mass number of sodium is 23 and atomic number is 11. Find out the number of protons and neutrons in the nucleus and give the arrangement of the distribution of electrons outside the nucleus.

3. The mass number of potassium is 39 and its atomic number is 19. Give its electronic configuration.

Expecting good answer.
Good Job guys!
Thanks in advance!


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Answer 1

Q1. What is the atomic structure of Hydrogen if it's atomic number is "1"?

Ans. We know that,

☆ Atomic number = No. of protons = No. of electrons

Therefore, hydrogen will have "1" electron in it's shell. For the atomic structure, please refer to the attachment :)

2. The mass number of sodium is 23 and atomic number is 11. Find out the number of protons and neutrons in the nucleus and give the arrangement of the distribution of electrons outside the nucleus.

Ans. We know that,

☆ Atomic number = No. of protons

Therefore,

➢ Number of protons = 11

Now, we have to find out number of neutrons,

$\large \bigstar \: \boxed{ \sf mass \: number \: = number \: of \: protons \: + number \: of \: neutrons}$

Therefore,

$\sf : \implies \: number \: of \: neutrons \: = 23 - 11 \\ \sf : \implies \: number \: of \: neutrons \: = 12 \: \: \: \: \: \: \: \: \: \:$

Now we have to find out the electronic configuration in Sodium.

Here, we will use the 2n² rule, which states that,

Number of electrons = 2n²

where,

• n = number of shell (orbits number)

So, According to this rule, the electronic configuration of sodium will be,

- K - shell = 2

- L - shell = 8

- M shell = 1

☆ More To know :-

• To become stable in nature, when the sodium forms ion, it, instead of gaining electrons, it loses 1 electron and becomes positively charged ion which is stable in nature.

• Atomic structure of sodium - Please refer to the second attachment

3. The mass number of potassium is 39 and its atomic number is 19. Give its electronic configuration.

Ans. Given,

• mass number of potassium = 39
• Atomic number = 19
• Number of electrons = atomic number = 19

Here, again we will follow the 2n² rule, and according to that, the electronic configuration of Potassium will be,

- K shell = 2

- L shell = 8

- M shell = 8

- N shell = 1

☆ More To know :-

• When potassium has to become stable in nature, then it loses one electron and becomes positively charged ion which is stable in nature i.e. doesn't react with other elements.

• The maximum number of electrons that can be accommodated by a particular shell is 8.

I hope that helps you @Atlas :))

Answer 2

$\large\red{ \underbrace{ \underline{ \boxed{ \tt{ \bigstar \: Bonjour \: mon \: ami}}}}}$

Here are your Answers :

__________________________

1] Atomic mass of Hydrogen = 1

this means, No. of neutron + No. of proton = 1

Atomic number of hydrogen = 1

This means, No. of proton = 1 .

Now, if No. of proton in hydrogen is 1, then the number of neutrons = 1-1 = 0

Also, every atom as the same number of electron and protons in it (unless an ion)

hence, number if electron = 1

Hence, An Atomic structure of an hydrogen Atomic contains :

• 0 neutron
• 1 proton
• 1 electron

__________________________

2] Mass number of sodium = 23

Hence, No. of (Proton + neutrons) = 23

Atomic number of sodium = 11

Hence, No. of protons = 11

Hence, numbers of neutrons = 23-11 = 12

As we know, the number of proton = number of electron

So, number of electrons = 11 .

The distribution of electron in Sodium is as follows :

In the first shell (K shell ) there are 2 electrons of sodium atom(and can't be more than that! ).

In the second orbit (L shell) there are 8 electrons and in the last orbit (M shell ) there is 1 electron revolving the nucleus.

• K shell = 2
• L shell = 8
• M shell = 1

Sometime, sodium atom also loses 1 atom of outermost shell to gain octate configuration. Hence, it transform into Sodium Ion (Na+) . then it has only 10 electrons.

*most of the metal are positively charged ion as they lose electrons.

Electronic configuration of Na = 1s2+2s2+2p6+3s1

__________________________

3] Mass No. of Potassium (K) = 39

Hence, No. of (Proton + neutron) = 39

Atomic number = 19

Hence, No. of proton = 19

Hence, No. of neutron = 39-19 = 20

As we know, no. of electron = no. of proton

or, No. of electron = 20

The first Shell (K shell ) contain 2 electron , then the next shell (L shell) contain 8 electron , the next shell (M shell) contain 8 electron* . The last shell (N ) shell contain 1 electron.

• K shell = 2
• L shell = 8
• M shell = 8
• N shell = 8

Hence, electronic configuration = 1s2+2s2+2p6+3s2+3p6+4s1

Note: The third shell can hold upto 18 electron. but we also know that the last shell of an electron can't contain more than 8 electron.

if 1 electron has been transferred to third shell, electronic configuration will be :

2,8,9

which is not possible.

__________________________

Know More :

• An atom can do any thing for achieving stability. Means, it should have either 2 electron or 8 electron at the outermost shell. For doing this they may lose or gain electron as per their need.
• If they lose electrons, the no. of proton will become greater, Hence the atom will become positively charged. It is said to be become an positively charged Ion .
• if they gain electrons, the no. of electrons would become greater, Hence the atom will become an negatively charged Ion.
• The naturally occurring stable Atoms are generally the Nobel gases. such as neon, argon, crypton, xenon etc.

If you have any other question, please ask me !