Question

He arranged elements in increasing order of atomic numbers.
Is a metal in period 2 having electronic configuration 2.1. [Beryllium/Lithium
Is a period having elements from atomic no. 11 to 18. (period - 1
The most reactive halogen from group 17. (chlorine/fluorine/ bron
Is the group number of the element whose atomic number is 4.18
suer of atomic numbers. Dobereiner/Moseley / Mendeleeff]
nfiguration 2,1. [Beryllium/Lithium/Sodium]
CC
les plus
ose atomic number is 4. [ group - 1/ group - 2/ group -18].
12​

Answer 1

Answer:

I don't understand your question

Explanation:

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Answer 2

1. Dimitri Mendeleev
2. Lithium
3. 3
4. Fluorine
5. Group-2