Final answer:
Only statements A and C about single replacement reactions are correct, which mention that a more reactive element replaces a less reactive one according to the reactivity series.
Step-by-step explanation:
To answer which statements about single replacement reactions are correct, we need to look at the options provided. The correct statements are as follows: A) A more reactive element replaces a less reactive element in a compound. This is indeed what happens in a single replacement reaction, according to the reactivity series, which helps to determine the likelihood of the reaction occurring. Another accurate statement is C) The reactivity series determines the likelihood of a reaction occurring. As for the incorrect statements, B) They are not known as double displacement reactions; rather, double replacement reactions are those which exchange the cations (or the anions) of two ionic compounds. And D) Single replacement reactions do not involve the exchange of ions between two compounds but rather one element in a compound is replaced by another single element.