When sodium is excited in a flame, two ultraviolet spectral lines at lambda - 372.1 nm and lambda = 376.4 nm respectively are emitted . which wavelength represented photons?
a) higher energy?
b) longer wavelengths?
c) higher frequences?

One significant difference between an ionic bond, where electrons are taken from one atom and added to another atom, and a covalent or metallic bond, where electrons are shared is

The atomic radius of sodium is 186 pm and of chlorine is 100 pm. the ionic radius for na+ is 102 pm and for cl– is 181 pm. in going from na to cl in period 3, why does the atomic radius decrease while the ionic radius increases? a. the inner electrons in the sodium cation shield its valence electrons more effectively than the inner electrons in the chloride anion do. b. the inner electrons shield the valence electrons more effectively in the chlorine atom than in the chloride anion. c. the outermost electrons in chloride experience a smaller effective nuclear charge than those in the sodium cation do. d. the outermost electrons in chloride experience a larger effective nuclear charge than those in the sodium cation do. e. monatomic ions are bigger than the atoms from which they are formed.

Nanotechnology, the field of trying to build ultrasmall structures one atom at a time, has progressed in recent years. one potential application of nanotechnology is the construction of artificial cells. the simplest cells would probably mimic red blood cells, the body's oxygen transporters. for example, nanocontainers, perhaps constructed of carbon, could be pumped full of oxygen and injected into a person's bloodstream. if the person needed additional oxygen-due to a heart attack perhaps, or for the purpose of space travel-these containers could slowly release oxygen into the blood, allowing tissues that would otherwise die to remain alive. suppose that the nanocontainers were cubic and had an edge length of 24 nanometers. part a part complete what is the volume of one nanocontainer? (ignore the thickness of the nanocontainer's wall.) express your answer using two significant figures. v v = 1.4ă—10â’20 l previous answers correct significant figures feedback: your answer 1.3824â‹…10â’20 = 1.382ă—10â’20 l was either rounded differently or used a different number of significant figures than required for this part. if you need this result for any later calculation in this item, keep all the digits and round as the final step before submitting your answer. part b suppose that each nanocontainer could contain pure oxygen pressurized to a density of 81 g/l . how many grams of oxygen could be contained by each nanocontainer?