Question 17

[bevhenkel5691]

hellO! I have never really heard the term electropositivity. could you explain that in terms of electronegativity as described in #19?

thanks

[mcat_premed3832]

Consider the carbonyl group C=O; the oxygen is towards the right of the periodic table so it is more electronegative than carbon. We thus assign delta (partly) negative to oxygen and delta positive for carbon. Electropositive literally means having a positive or partially positive charge like the carbon in the carbonyl group.

Electropositivity, therefore, is the opposite of electronegativity. Thus for Answer choice B in Q17, increasing electropositivity as one goes down a period = decreasing electronegativity.

[diana.chen2541]

Hello,
Is it correct to think of the question in this way:

An increase in stability would mean that the electron cloud is less dense (fewer electrons), thus less reactive. Since we have an increase in electropositivity as you go down Group VII, this means that electrons are further away from the nucleus due to the increase in atomic radius, we will have a less reactive molecule, thus more stable.

Thanks in advance

[mohsinalam5969]

@ bevhenkel5691
Electronegativity, symbol χ (the Greek letter chi), is a chemical property that describes the tendency of an atom or a functional group to attract electrons (or electron density) towards itself and thus the tendency to form negative ions.
while
Electropositivity is a measure of an element's ability to donate electrons, and therefore form positive ions; thus, it is opposed to electronegativity. Mainly, this is an attribute of metals, meaning that for the most part, the greater the metallic character of an element, the greater the electropositivity. Therefore the alkali metals are most electropositive of all. This is because they have a single electron in their outer shell and, as this is relatively far from the nucleus of the atom, it is easily lost; in other words, these metals have low ionization energies.
e.g Consider the carbonyl group C=O; the oxygen is towards the right of the periodic table so it is more electronegative than carbon. We thus assign delta (partly) negative to oxygen and delta positive for carbon.

@diana.chen2541
yeah u are right...Welcome