Question

1) Write the names of first 20 elements of periodic table in correct sequence

2) Who discovered electrons, protons and neutrons?

3) Atomic number of an elemnt is represented by ________.

4) What is electronic configuration? Who suggested it? Write the electronic configuration of Argon, Potassium amd Calcium


(Atleast answer any three.)

Answer 1

⭐⭐⭐⭐⭐ ANSWER ⭐⭐⭐⭐⭐


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✔ The first 20 elements in the PERIODIC TABLE in correct sequence are :

➡ Hydrogen
➡ Helium
➡ Lithium
➡ Beryllium
➡ Boron
➡ Carbon
➡ Nitrogen
➡ Oxygen
➡ Fluorine
➡ Neon
➡ Sodium
➡ Magnesium
➡ Aluminum
➡ Silicon
➡ Phosphorus
➡ Sulphur
➡ Chlorine
➡ Argon
➡ Potassium
➡ Calcium

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✔ DISCOVERIES
➡ Electrons were discovered by J. J. Thomson.
➡ Protons were discovered by E. Goldstein
➡ Neutrons were discovered by James Chadwick.

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✔ ATOMIC NUMBER OF AN ELEMENT IS REPRESENTED BY THE LETTER 'Z'.

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✔ ELECTRONIC CONFIGURATION

➡ The distribution of electrons into different shells (orbits) of atoms of an element is called its ELECTRONIC CONFIGURATION.

➡ It was suggested by Bohr and Bury.

➡ Argon : (2,8,8)

➡ Potassium : (2,8,8,1)

➡ Calcium : (2,8,8,2)
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⭐⭐⭐ ALWAYS BE BRAINLY ⭐⭐⭐

Answer 2

1)Hydrogen,Helium,Lithium,Berelium,Boron,Carbon,Nitrogen,Oxygen,Fluorine,Neon,Sodium,Magnesium,Aluminium,Silicon,Phosphorus,Sulphur,Chlorine,Argon,Pottasium,Calcium.

2)Electron-J.J.Thomson
Proton-E.Goldstein(Rutherford)
Neutron-Chadwick

3)Atomic number is represented by 'Z'.

4)Electronic configuration means putting the electrons into the correct shell.It was suggested by Niels Bohr.
Electronic configuration of-
Argon=2,8,8
Pottasium=2,8,8,1
Calcium=2,8,8,2.

Mark as brainliest if it helped.