Reef Chemistry Question of the Day #170 Atomic Weight

[Randy Holmes-Farley]

Reef Chemistry Question of the Day # 170

Which of the following has the highest atomic weight?
In other words, which of the following weighs the most for a single atom.

A. Iron
B. Potassium
C. Copper
D. Iodine

Try without looking it up!
Good luck!

[Note, the first version of this question asked for molecular weight, but since these are all atoms, atomic weight is the better term for it]


























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[revhtree]

I vote A.

 

[143MPCo]

D

 

[gtbarsi]

I think D is the correct answer. As I recall Iron is fairly light and Copper is only slightly heaver that Iron.

 

[Cory]

I think its iron

Why do we say molecular weight, when asking for the weight of a single atom? I thought a molecule consisted of two or more atoms?

 

[jaws789832]

Flourine, chlorine Bromine then iodine. so its 4th down from the top of the chart. (you are really making me try and remember my haz mat training here). I believe all the others are higher on the chart so I will go with D, Iodine

 

[ianf77]

D

 

[samba_dad]

It's been a long time since CH101, but if I recall correctly you are looking for the element closest to the bottom of the periodic table. I don't remember the elements, but I remember H has a weight of 1 (can't recall units g/something)? That's somewhat irrelevant. So I would say whatever is lowest on periodic table. I am going to guess Cu.

 

[Ebone]

D... (side note: I have a periodic table shower curtain) so didn't formally look it up but have looked a few times... so hopefully I'll be correct or else I'll need to shower longer from now on

 

[JimWelsh]

Without looking it up, I'm going with D. Iodine. And I agree with Cory: Isn't the correct term in the context of discussing single atoms "atomic weight"?

 

[Randy Holmes-Farley]

I think its iron

Why do we say molecular weight, when asking for the weight of a single atom? I thought a molecule consisted of two or more atoms?

Sorry, I probably should have said atomic weight in this instance. Most chemists casually use molecular weight to cover atoms too, but technically it probably isn't correct.

So I changed it.

 

[Lynn52]

D iodine

 

[beaslbob]

seems to me like the heaviest most dense atom will sink to the bottom of the list. So I say

d

 

[Randy Holmes-Farley]

seems to me like the heaviest most dense atom will sink to the bottom of the list. So I say

d

Excellent!

 

[Randy Holmes-Farley]

duplicate

 

[Taservices]

D

 

[Randy Holmes-Farley]

And the answer is...D. Iodine by a huge margin, in fact!

Good going folks. Most people got this right.

The rank order is:

Element Atomic Weight
Iodine..............126.9 g/mole
Copper..............63.5
Iron..................55.8
Potassium...... ..39.1


Happy Reefing!