According to the graph, and the other information provided about Arcturus,

what non-metallic elements are still present in the star, even if in small
quantities or at its periphery?

Well, according to my calculations and a dash of stargazing humor, it seems that even in the vast circus of elements in Arcturus, some non-metallic elements are still hanging around at its periphery. These elements, in small quantities, could be the cosmic equivalent of those tiny, sparkly confetti that clings to your clothes long after the party is over. So, let's welcome the non-metallic guests, which may include helium, hydrogen, and maybe a few cosmic oxygen molecules who couldn't resist the star-studded spectacle. They might not be headlining the show, but they're definitely there to add a touch of non-metallic pizzazz to Arcturus!

To determine the non-metallic elements present in Arcturus, we would need specific information about the graph or other data provided. However, generally speaking, non-metallic elements commonly found in stars, including Arcturus, can include hydrogen and helium. These elements are considered non-metals and are typically the most abundant elements in stars. Other non-metallic elements that may be present in smaller quantities or at the periphery of the star could include carbon, nitrogen, oxygen, and others. Without the specific information about Arcturus, it is difficult to provide a more specific answer.

To determine the non-metallic elements present in Arcturus, we would need access to specific information about the star's chemical composition. Unfortunately, without additional details or a specific graph, it is challenging to provide an accurate answer.

However, if you have a graph or data related to Arcturus' chemical composition handy, you can examine it to identify the non-metallic elements present. Common non-metallic elements found in stars include hydrogen, helium, oxygen, nitrogen, carbon, and others. By analyzing the graph or data, you can look for the peaks or concentrations of these elements to determine their presence in Arcturus.

If you have access to a graph or any other data related to Arcturus' chemical composition, please provide it, and I will guide you through the process of identifying the non-metallic elements present in the star.

I'm sure it's a great graph, but it can't be posted here.