What are the components needed in order for an experiment to be valid

Achange in the number of neutrons in an atom will change an blank . when the number of protons changes in an atom, a new element will form.

Jose and eric were given four samples in lab. the results of their analysis are shown in the table. based on the data they collected, which sample is most likely a metal?

You open a can of soda at room temperature and hear a hiss. which of the following factors has changed inside the container? a.) atmospheric pressure b.) temperature of gas c.) type of gas d.) amount of gas