From Earth, a hydrogen source releases an emission line that has a wavelength of 410nm. Observations have been made for the same line in the spectrum of light from a distant star. The star has a wavelength of 485nm (shifted toward the red end of the spectrum). Provide an explanation for the differences in wavelength that were observed.

1) how many electrons are in each energy level of the following elements? a. he b. na c. na d. ne 2) how many valence electrons are percent in the following atoms? a. s b. mg c. be d. cl 3) which of the following elements are stable as atoms? a. he b. o c. cl d. ar if you are able to provide the work as to how you got the answers that would be greatly appreciated. : )

Some familiar products contain some of the same types of atoms. for instance, the chemical formula for baking soda is nahco 3. the chemical formula for liquid bleach is naclo, and the chemical formula for table salt is nacl. which choice best describes why these three products have some of the same types of atoms in common?

There are approximately 15 milliliters (ml) in 1 tablespoon (tbsp). what expression can be used to find the approximate number of milliliters in 3 tbsp?