Si la vela se consume uniformemente a 0,2 cm/s, ¿con qué velocidad se desplaza el extremo de la sombra que se proyecta en la pared vertical, debido a la barra opaca frente a la vela

Only one reactant yields 2 or more products. meaning you will only have 1 product and it will break down into 2 or more products. eg. h2o -> h2 + o2

Cause its being chemically applied?

☆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