When a copper salt such as Cu(NO3)2 is burned in a flame, a blue-green color is emitted. Which figure represents the emission spectrum for the element copper? (LO 5.6)? (a)

(b)

(c)

(d)

Video transcript

Welcome back everyone. We're told that metal ions of Group one elements can be identified using a flame test a compound containing sodium ions amidst an orange flame. When burned, identify the emission spectrum for sodium. So, we want to first consider that our ion according to the prompt is emitting a orange flame based on the flame test. And we can see out of the four diagrams below, we have the color orange reflected definitely by the emission lines seen in choice C. It's occurring at around 650 nanometers of wavelength. So we can say that recall. That wavelength is represented by lambda is equal to nanometers where we see our orange radiation on our visible light spectrum. We want to recognize that because choice c. depicts these emission lines specifically around 650 nm reflecting our orange color here. That this is going to be a line emission spectrum which is identified by only particularly Wavelengths covered by certain emission lines within a given range of values. And we can see that this value ranges from around 650 nm where we find the color orange. Now we can automatically rule out choice A. Because we can see that our emission lines are falling on the color blue at around 460 nanometers. So we would rule this out. We don't want to consider choice A. It's incorrect. Now between choices B. D and C, we see that choices B and C. Do cover emissions that fall around the orange color here. However, we can see that choice is B and C. Are continuous emissions. So we have a continuous range of wavelengths reflected under various colors here. So they cover all of the different radiations that we see on our visible light spectrum. And that is not what our prompt tells us. We observe. We observe only the color orange from our sodium ions. So we would recognize choices B and D will say choices B and D. Are continuous emission spectrum spectrums and because we know that our ion only emits one sort of color, this tells us that we should only confirm as our final answer choice choice C, which is a line emission spectrum where we observe the color. We observe emission lines at the color orange around nanometers on our visible light spectrum. So Choice C. Is our final answer. I hope everything that I reviewed was clear. If you have any questions, leave them down below and I'll see everyone in the next video