Which of the following is NOT a molecule ? (1 Viewer)

[pacman911]

[FONT=&quot]Which of the following is not a molecule?

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(B) N_2<o></o>
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(C) NH_3<o></o>
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(D) Al


The answers say D, but I have no clue why.
Can anyone explain ?
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[thongetsu]

Al is just an atom, Aluminium.

 

[pacman911]

But then isn't He an atom ?

 

[randomnessss]

But then isn't He an atom ?

Helium is a monatomic molecule (i.e. a molecule that consists of one atom only).

 

[thongetsu]

oh didn't see He, hmmm...dunno :S

 

[pacman911]

I don't get it, if that's the case, then wouldn't Al also be a monoatomic molecule ? :S

 

[thongetsu]

monatomic means 1 atom?

 

[Omie Jay]

all noble gases are monatomic because their full outer shells/orbits mean they cant, and dont need to, bond with anything else

 

[Omie Jay]

Al has a valency of +3 i think

 

[thongetsu]

and that makes them molecules?

 

[Omie Jay]

Molecule - Wikipedia, the free encyclopedia

In the kinetic theory of gases, the term molecule is often used for any gaseous particle regardless of its composition. According to this definition noble gas atoms are considered molecules despite the fact that they are composed of a single non-bonded atom.[3]

^ i agree with that

also it makes sense when u think about it.

 

[thongetsu]

oh ok.

 

[pacman911]

Thanks alot

 

[mirakon]

no, as Helium is a noble gas, it exists as a monatomic molecule. Metals/ionic compounds do not form molecules. Molecule is a term that applies purely to non-metals. Therefore Aluminium is not a molecule

 

[ohexploitable]

Board of Studies definition: "particles which can move independently of each other"

He atoms, N₂ molecules and NH₃ molecules are gangsta and move around and do whatevs. Al atoms share metallic bonds with each other and can't move independently.