The emission spectrum for an element is
select all that apply.
a. specific to each different element
b. the same for all elements in the same group
c. used to identify an unknown substance
d. is not specific to an element and changes constantly

The answers are A) specific to each different element and C) used to identify an unknown substance. The emission spectrum is the spectrum of frequencies of electromagnetic radiation. This radiation emitted due to the transition making from a high energy state to a lower energy state of an element.

Then the answer would be d then