What causes the lines in the emission spectrum for elements?

a continuous release of energy from the heated element
a quantum absorption of energy as various electrons are excited to a higher energy level
a quantum release of energy as electrons drop back to their ground state
none of the above

Five students had to answer the question how are elements arranged in a periodic tabledamon: i think the elements are arranged by increasing massflo: i think the elements are arranged according to their properties sienna: i think the elements are arranged by when their discovers kyle: i think the elements are arranged according to how common they areglenda: i don't agree with any of themwho is right

Define the kinetic molecular theory

What is a number added in front of a formula in order to balance the equation