Answer:
A molecule of water has two hydrogen atoms. Both of these atoms can form a hydrogen bond with oxygen atoms of different water molecules. Every water molecule can be hydrogen bonded with up to three other water molecules
For your question about diagram it is definitely A
Answer:
The number of valence electrons in an atom is reflected by its position in the periodic table of the elements (see the periodic table in the Figure below). Across each row, or period, of the periodic table, the number of valence electrons in groups 1–2 and 13–18 increases by one from one element to the next
Alchemists studied chemical reactions before chemistry was a word
