Electro negativity increases along the period and decreases along the group.
Electro positivity is the inverse of that.
Therefore,
Cesium is highly electropositive (Cesium is the most electropositive stable element. Francium is more electropositive (at least in theory) but only about 30 grams exists on the entire planet as it is highly radioactive so no one has been able to check.)
Flourine is the most electronegative element.