Question

Write your question here (Keep it simple and clear to get the best answer) write down the first 20 element in the their atamic number atamic Mass in your exeiase.

Answer 1

Answer:first 20 elements of the periodic table, their atomic ... This is also the number of protons in each atom. ... Elements that have names ending with -ine belong to a group

Explanation:

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Answer 2

H    1    1

He  2   4

Li    3   7

Be  4   9

B    5   11

C    6    12

N    7    14

O    8    16

F      9   19

Ne   10  20

Na   11    23

Mg    12   24

Al      13    27

Si      14     28

P       15     31

S       16      32

Cl      17      35.5

Ar       18     40

K         19    39

Ca       20    40