Why are polar bears listed as a threatened species?

|using the periodic tablewarm-upuse the periodic table in the tools bar to answer the following questions. what elemental classification does oxygen belongto? done

I'm learning about the periodic tables and what each subject's configuration is. for example, hydrogen is 1s^1, but i don't understand how you get that. can someone me understand how to figure out how to figure this out? sorry if the question makes no sense, but it would really a lot if you could me understand! you so much if you can!

How do you interpret a chromagram for what mixtures contain?