Which of the following will best help determine the direction of heat flow in a system?

There are main groups in the modern periodic table of elements

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

What is the polyatamic ion of thiosulfate