更新1:
I mean, when u shake the can of soft drink, CO2 will form from the bicarbonate solution then increases the air pressure inside the can. After opening the can, more CO2 will be formed because the air pressure decreases.
更新2:
This is my observation, people use the tip of their fingers to hit the outside of the can before opening. They say that it would help the gas come out but instead the gas itself. PLEASE EXPLAIN WHY!!!
更新3:
Thank you!!