Lithium 6 would have 6 valence electrons in the outer orbital, while lithium 7 would have 7 in the outer orbital.
"The sun radiates radiation in the UV, visible and infra-red regions of the spectrum. <span>When this reaches earth, some is reflected off the atmosphere/ clouds back into space. However, some passes through. UV </span>radiation<span> ionises molecules in the </span>thermosphere<span>, and this is the cause of the aurora." Credits to Google
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