“ Single replacement reactions” are chemical reactions where, in some cases, metals REPLACE other metals that are in a solution.
Think about it like these people. Orange shirt guy is by himself. He is “bigger” and “stronger” than the guy in the white shirt Orange shirt guy wants to dance with the girl, so because his can, he “kicks out” the guy in the white shirt and takes his partner… leaving white shirt guy all alone
How do we know if one metal is “bigger” or “stronger” than another and can kick it out and take it’s partner? THE METAL ACTIVITY SERIES! If a metal is ABOVE it on the activity series, then it is “stronger” than it, “more reactive” than it, and CAN kick it out and take it’s place.
This makes the metal at the TOP of the series the MOST reactive metal, and the one at the bottom the LEAST reactive metal . Lithium can kick out all other metals and take their place. Gold can not replace anything… it does not react with any other metallic solutions. Including acids .
HALOGENS also do single replacement reactions They work the same way, EXCEPT that the halogen replaces the SECOND half of the compound (The other halogen) In order for a halogen to “kick out” another halogen and take it’s place, it must be ABOVE it in the periodic table
A halogen single replacement reaction looks like this in equation form: A + BC -> BA + C Where “A” kicks out “C” and takes it’s place… A + C B -> BA + Try some….