The mass number is used to calculate the number of —————— in one atom of an element.

Pbco3 –> pbo+ co2. how many liters of carbon dioxide gas is produced from the decomposition of 32 grams of lead (ll) carbonate?

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

Predict whether the changes in enthalpy, entropy, and free energy will be positive or negative for the boiling of water, and explain your predictions. how does temperature affect the spontaneity of this process?