It's the rows. They are periods. (1,2,3,4,5,6,7 - the ones without the letters).
Answer : The question is to write the elements alphabetically and seperating them with commas.
So in this case for your question of Fireworks , K
,
The answer will be
K, N, O.
You have to just differentiate the elements and write them according to the alphabetical order.
Answer:
the invention of the microscope has made seeing bacteria/cells, examining forensic evidence (such as fingerprints), studying atomic structure, tissue analysis, and the study of our ecosystem possible to the naked eye
Explanation:
hope this helps
Answer:
Na + O.2 = NaO.2 whereas Cu + AgNo3 = Cu.2No.3 +AG