A beaker and a microscope
Answer:
Electrical force can pull and push
Explanation:
Answer:
the wavelength of radiation emitted is 
Explanation:
The energy of the Bohr's hydrogen atom can be expressed with the formula:

For n = 7:


For n = 4


The electron goes from the n = 7 to the n = 4, then :


Wavelength of the radiation emitted:

where;
hc = 1242 eV.nm

