Radicals that allow kanji to have same reading
I've read that there are seven radicals (?) that, when are in either all or most kanji, that they will all share the same on-Yomi as the radical.

工星奂 are three so far, I don't know the other four

工 (“craft”). It is pronounced kou (こう) and all are pronounced kou:

紅 (“crimson”)
空 (“empty”)
虹 (“rainbow”)
江 (“creek”)
攻 (“aggression”)
功 (“achievement”)
All are read as 'kou'

What are the four other radicals (or more, if any?) will they all have the same reading, or just some kanji?

Many thanks in advance

Question

Radicals that allow kanji to have same reading
I've read that there are seven radicals (?) that, when are in either all or most kanji, that they will all share the same on-Yomi as the radical.

工星奂 are three so far, I don't know the other four

工 (“craft”). It is pronounced kou (こう) and all are pronounced kou:

紅 (“crimson”)
空 (“empty”)
虹 (“rainbow”)
江 (“creek”)
攻 (“aggression”)
功 (“achievement”)
All are read as 'kou'

What are the four other radicals (or more, if any?) will they all have the same reading, or just some kanji?

Many thanks in advance

Answer

The on-yomi reading for 空 is くう, as in 空気(くうき) or 空港(くうこう), so yes, there are exceptions to this rule.
In regards to the reading being the same for kanji containing a certain radical, there's more information on that in Heisig's "Remembering the Kanji 2" and there are more than seven examples listed there.

Answer

Technically not radicals, but more bigger part put still:
1.  旬 - every kanji with a part that combines has this kanji as one of its part is pronounced じゅん with the exception of 絢 but the name reading of this kanji is also じゅん.
2.  君 - every kanji read as くん or ぐん with one exception as きん
3. 元 - (radical) almost always かん or がん, 院 being an exception.
you can search for more

Answer

In Chinese MOST kanji have this feature. Since ON-yomi is derived from Chinese, I suspect it is more than 4 or 6 or even ten radicals that have this feature. I have noticed it quite often, but I can't list them from the top of my head right now.

Não perca a oportunidade de aprender uma língua no conforto da sua casa. Navegue pela nossa seleção de professores de línguas experientes e inscreva-se na sua primeira aula agora mesmo!