While studying yesterday, I came across two words with the suffix さ:
無邪気さ(translated as innocence) and 寛大さ (translated as generosity).
1) What's the difference between these words and the words without the さ? I thought that な-adjectives without the な are already nouns.
2) Can I add さ to other 形容動詞 too, for example 人気さ or 便利さ?