What is another name for the rare earth elements? a.
Group 1
c.
Group 6
b.
Lanthanide
d.
Alkaline Earth

Why do atoms emit energy of only specific wavelengths

50.)the diagram below represents the wave fronts produced by a point source moving to the right in a uniformmedium. observers are located at points a and b.compared to the wave frequency and wavelength observed at point a, the wave observed at point b has a(1) higher frequency and a shorter wavelength(2) higher frequency and a longer wavelength(3) lower frequency and a shorter wavelength(4) lower frequency and a longer wavelength

The researcher who studied the ability of cats to learn to escape from puzzle boxes was