need help on Dr collin Chemsitry question

[cliub]

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There is a question from Dr collin Chem section about why do the elements sodium and chlorine bond so readily?

The answer Dr collin give is electron exchange caused by low ionization energy for sodium and low electron affinity for chlorine.

I thought Chlorine should have a high electron affinity(easy to add electron), on the answer key say Low electron affinity (easy to add electron). now i am confused

 

[Timbo]

sounds wrong. halogens, including chlorine, have high electron affinity. Electron affinity increases as you move up and to the right of the periodic table.

 

[Bigj5768]

your 100% correct. Sodium has a low ionization energy and chlorine has a high electron affinity.

 

[beanie92]

Well in his answer explanation, he did say that the answer could be confusing because it can be either high or low electron affinity for Chlorine, on the PCAT the correct answer might be high electron affinity, but what he said was the right way to say is low because they are negative numbers 😀

So I guess "high e affinity" means the absolute value and "low e affinity" is the actualy number, the nagative sign makes it low?

 

[Chemicals]

Found another one:

It asks "If an atom's valence electrons are tightly held then we can expect a.."

Answer: High ionization energy and a low electron affinity...

shouldn't it be a high electron affinity?

 

[JonPrePharmD]

Found another one:

It asks "If an atom's valence electrons are tightly held then we can expect a.."

Answer: High ionization energy and a low electron affinity...

shouldn't it be a high electron affinity?

There is a solution where he talks about the words "high" and "low" being somewhat confusing due to the charges, and that there is "no way around it" or something. Basically, he says that he doesn't know which way the PCAT will word the answers. Does high mean extremely negative? It should, but it some cases, it can mean closer to 0.

Here is the best explanation I can find.

Question:
If an atom's valence electrons are tightly held, then we can expect a high ionization energy and a low electron affinity

Would the atom also have a high electronegativity? Also, why would atom have low electron affinity?

Answer:

In the above explanation, he uses "Low" in the sense that it's more negative, so think of a large negative number like -439kJ/mol.

Really the confusion can be eliminated if they asked greater or smaller electron affinity, instead of high or low...

Taken from: http://www.chemguide.co.uk/atoms/properties/eas.html

"[FONT=Helvetica, Arial]as you go down the group, first electron affinities become less (in the sense that less energy is evolved when the negative ions are formed)...".

 

[cjorges]

Since you guys are talking about chemistry, what do you guys think are the chances of a SN1, SN2, or markovnikov question coming up in the test?

 

[JonPrePharmD]

Since you guys are talking about chemistry, what do you guys think are the chances of a SN1, SN2, or markovnikov question coming up in the test?

Very likely on all three. Also anti-markovnikov.