List 4 signs that show evidence of a chemical reaction

Change in color, change in temp, formation of gas, or formation of precipitate

☆ionisation energy increases across a period from na -> ar☆ionisation energy decreases down a group from li -> fr☆ionic radius decreases across a period from na -> cl☆ionic radius increases down a groupfrom f -> ii hope it clarifies your doubts

Ionic compounds dissociate into component ions dissolved into a solution creating substances called "electrolytes".hope my answer has you : )