Given the following: 42.07 % Na, 18.89% P and 39.04%0, determine the
empirical formula

☆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

What do you not know about it

Your question is not clear but if you can explain yourself i would be glad to .  just trying to : ))