Hey there!:
<span>Use the Avogadro constant :
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1 mole -------------- 6.02*10²³ molecules
0.0524 moles -------- molecules H2O
molecules H2O = 0.0524* ( 6.02*10²³) / 1
molecules H2O = 3.15*10²² / 1
= 3.15*10²² molecules H2O
Because they have a full outer shell and they are both noble gases
Generally (but far from universally), the elements within a group have similar characteristics. Antimony, nitrogen, and arsenic are all part of the same group as phosphorous (the pnictogens, or group 5A). Oxygen is not in this group, but rather in an adjacent group (the chalcogens, or group 6A). Thus, the answer here should be oxygen.
That said, there can be very significant differences in characteristics among the elements within a group, and that is certainly the case here. For example, free nitrogen exists predominantly as a molecular gas (N₂) and makes up about 78% of the atmosphere we breathe. Elemental arsenic (As), while in the same group as nitrogen, is naturally found in the solid state and is poisonous to humans (arsenic is sometimes included among the toxic heavy metals, although it’s technically a metalloid).
Answer:
Metals and non-metals are substances that can be differentiated on the basis of various physical and chemical properties. Metals are the elements that are generally hard as strong metallic bond exists between the atoms. As against non-metals are the elements which are usually soft.