Question

A table of the visible light spectrum is shown below.

A 2 column table with 6 rows. The first column is labeled color with entries red, orange, yellow, green, blue, purple. The second column is labeled wavelength in nanometers with entries 700 to 635, 635 to 590, 590 to 560, 560 to 490, 490 to 450, 450 to 400.

Tyrone analyzes the emission spectrum of an unknown element. He observes two discrete lines at 600 nm and 650 nm, and he sees many lines corresponding to shorter wavelengths, with the strongest line being at 475 nm.

Which emission spectrum is Tyrone most likely analyzing?

A line spectrum with one black line in purple, blue, light blue and red.
A line spectrum with 3 black lines in purple, one black line in blue, 2 black lines in light blue, one black line in orange and one black line in orange-red.
A line spectrum with 3 black lines in purple, 2 black lines in blue, 2 black lines in light blue, one black line in green and one black line in yellow.
A line spectrum with 4 black lines in blue, 6 black lines in green, 3 black lines in yellow and one black line in orange.

Answer 1

650 nm is in the red range (700–635 nm), 600 nm is in the orange range (635–590 nm), and 475 nm is in the blue range (490–450 nm). Tyrone therefore sees one red line, one orange line, and many shorter-wavelength lines with the strongest at blue. Only the second choice shows both an orange and an orange–red (red) line plus many lines at shorter wavelengths, so choose the second option.