the big bang theory states

a. the universe is contracting

b. the universe began as a small, dense ball of matter

c. the universe will explode

d. the universe cannot expand anymore

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 reaction is taking place? 02 + c3h8 = h20 + co2

A50.0g sample of liquid water at 0.0 c ends up as ice at -20.0 c. how much energy is involved in this change?