They all look like there decaying and was left out or sat inside too long
B
Electrons are found in shells or orbitals that surround the nucleus of an atom
"As we move through the visible spectrum of violet, blue, green, yellow, orange and red, the wavelengths become longer. The range of wavelengths (400 - 700 nm) of visible light is centrally located in the electromagnetic spectrum (Fig. 1)."
-https://www.asu.edu/courses/phs208/patternsbb/PiN/rdg/color/color.shtml
No "ion" is electrically neutral. If it's an ion, then it's charged.
"There are three rules on determining how many significant figures are in a number: Non-zero digits are always significant. Any zeros between two significant digits are significant. A final zero or trailing zeros in the decimal portion ONLY are significant."
