Why is the forward reaction rate of a system in chemical equilibrium not equal to zero?

Two friends at different locations want to communicate with each other by sending low energy signals. which of the following methods can they use to communicate? a) produce x-rays using colliding electrons and send them to radios, which capture sound b) send messages using infrared radiation, which travel in the form of waves c) send radio waves through intervening media like radio and television d) produce sound waves using microwaves from heated objects

Why does his teacher ask him to balance the equation by including the correct coefficient

How have the greenhouse gasses increased from the year 2000 to 2018