Which of the following statements is correct for isotopes of an element?

Match the mixture with the substance// i really need on this guys (it’s a pic btw)

An atom's configuration based on its number of electrons ends at 3p4. another atom has seven more electrons. starting at 3p, what is the remaining configuration? 3p63d34s2 3p43d54s2 3p64s23d3 3p44s23d

Acontrol during an experiment. might change remains constant does not exist does change