How did u learn your elements and the symbol from the periodic table?

Which is a character of nuclear fusion but not nuclear fission

How are elements arranged in a periodic table

Zoe is investigating the composition of substance a, an unknown substance. using chemical processes, she analyzes substance a and determines it is composed of sodium, oxygen, and hydrogen atoms in a ratio of 1 : 1 : 1. what is substance a? a. a compound b. an element c. a heterogeneous mixture d. a homogeneous mixture