Question

write the elements 1 to 20 with their atomic number and atomic mass

Answer 1

ATOMIC NUMBER ||||||||ATOMIC MASS
1.Hydrogen. --------. 1
2.helium. -------------. 4.0
3.lithium. --------. 6.9
4. beryllium 9.0
5.Boron 10.8
6.carbon. 12.0
7.nitrogen. 14.0
8.oxygen= 16
9.fluorine =19
10.neon =20.2
11. sodium. =23
12. magnesium

14. silicon
15.phosphorus
16.sulphur
17. chlorine
18. argon
19. potassium
20. calcium

Answer 2

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