What is the oxidation number of carbon in the compound carbon dioxide, CO2? A) +3
B) +2
C) -3
D) +4

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

How could a student test the effect of removing heat from a gas that is stored in a sealed container? what must occur in order for matter to change states?

Achemical reaction is done in the setup shown, resulting in a change of mass. what will happen if the same reaction is done in a sealed container that is placed on the electronic balance?