Give an atomic number, atomic symbol, atomic mass of the first 20 elements

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Here is a list of the first 20 elements with their atomic number, atomic symbol, and atomic mass:

Element Atomic Symbol Atomic Number Atomic Mass
Hydrogen (H) 1 1.0079
Helium (He) 2 4.0026
Lithium (Li) 3 6.941
Beryllium (Be) 4 9.0122
Boron (B) 5 10.81
Carbon (C) 6 12.0107
Nitrogen (N) 7 14.01
Oxygen (O) 8 16.00
Fluorine (F) 9 19.00
Neon (Ne) 10 20.18
Sodium (Na) 11 22.99
Magnesium (Mg) 12 24.31
Aluminum (Al) 13 26.98
Silicon (Si) 14 28.09
Phosphorus (P) 15 30.97
Sulfur (S) 16 32.06
Chlorine (Cl) 17 35.45
Argon (Ar) 18 39.95
Potassium (K) 19 39.10
Calcium (Ca) 20 40.08

Periodic Table First 20 Elements

Periodic Table First 20 Elements

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CBSE CLASS XII Related Questions

  • 1.
    Following reaction takes place in one step:

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    How will the rate of above reaction change if the volume of the reaction vessel is decreased to one third of its original volume? Will there be any change in the order of reaction with the reduced volume?


      • 2.

        A reaction \( \mathrm{A \rightarrow B} \) follows second order kinetics. How will the rate of reaction be affected if the concentration of (i) A is increased by three times, and (ii) A is reduced to half ?


          • 3.

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                • 5.
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                    • 6.
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                        CBSE CLASS XII Previous Year Papers

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