Question

Name first 20 elements of periodic table.. Tell atomic number and atomic mass? ​

Answer 1

Answer:

1.H

2.He

3.Li

4.Be

5.B

6.C

7.N

8.O

9.F

10.Ne,Na,Mg,Al,Si,P,S,Cl,Ar,K,Ca

Answer 2

Explanation:

Atomic

No. Symbol Name Atomic Mass (amu, g/mol)

1 H Hydrogen 1.00797

2 He Helium 4.00260

3 Li Lithium 6.941

4. Be Beryllium 9.01218

5 B Boron 10.81

6 C Carbon 12.011

7 N Nitrogen 14.0067

8 O Oxygen 15.9994

9 F Fluorine 18.998403

10 Ne Neon 20.179

11 Na Sodium 22.98977

12 Mg Magnesium 24.305

13 Al Aluminum 26.98154

14 Si Silicon 28.0855

15 P Phosphorus 30.97376

16 S Sulfur 32.06

17 Cl Chlorine 35.453

18 Ar Argon 39.948

19 K Potassium 39.0983

20 Ca Calcium 40.08