Question

20 elements and atom​

Answer 1

Answer:

Hydrogen, oxygen, nitrogen, helium,argon,magnesium, krypton, potassium , sulfer ,lithium, chlorine, silicon, sodium,aluminum, carbon, beryllium, fluorine, boron, phosphorus, neon.

Answer 2

Answer:

1 H - Hydrogen

2 He - Helium

3 Li - Lithium

4 Be - Beryllium

5 B - Boron

6 C - Carbon

7 N - Nitrogen

8 O - Oxygen

9 F - Fluorine

10 Ne - Neon

11 Na - Sodium

12 Mg - Magnesium

13 Al - Aluminum

14 Si - Silicon

15 P - Phosphorus

16 S - Sulphur

17 Cl - Chlorine

18 Ar - Argon

19 K - Potassium

20 Ca - Calcium