Plz help I need help plz ASAP

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

Convert the temperature of dry ice, –77 ∞c, into degrees fahrenheit and kelvin.

What methods could you use to solubilize calcium carbonate