It's 1 because there is only one electron on the outer shell.
Molar mass H₂O = 18.0 g/mol
number of moles :
1.0 / 18.0 => 0.055 moles
1 mole -------------- 6.02 x 10²³ molecules
0.055 moles -------- ? molecules
molecules = 0.055 x ( 6.02 x 10²³) / 1
molecules = 3.311x10²² / 1
= 3.311 x 10²² molecules
hope this helps!
<h3>Ferric Oxide:-</h3>


<h3><u>C</u><u>a</u><u>l</u><u>c</u><u>i</u><u>u</u><u>m</u><u> </u><u>H</u><u>y</u><u>d</u><u>r</u><u>o</u><u>x</u><u>i</u><u>d</u><u>e</u><u>:</u><u>-</u></h3>


Answer:
<u><em>METALS</em></u>
Lose their valence electrons easily/ ionic by electron loss.
<u><em>NOMETAL</em></u>
Gain or share valence electrons easily/ ionic by electron grain.