Question

note: to answer some of the questions, it may help to reference a periodic table. examine the image. unknown sodium lithium calcium strontium barium sheila terry/photo researchers/science source modified by flipswitch. what is the identity of the unknown element?

Explanation:

Step1: Compare spectral lines

Compare the spectral - line pattern of the unknown element with those of known elements (sodium, lithium, calcium, strontium, barium).

Step2: Identify matching pattern

The spectral - line pattern of the unknown element matches that of strontium.

Answer:

Strontium