Copper has 29 electrons, and its electron configuration is:
1s2 2s2 2p6 3s2 3p6 3d10 4s1.
Therefore, copper has 1 valence electron.
Hope this helps~
Please add a picture of what numbers ; )
Answer : (C) "Higher frequencies have larger spaces between lines".
Explanation:
In Young's experiment, the condition for constructive interference is given by :
.........(1)
n is order or number of lines observed
d is distance between slits
is the angle between the path and the line from screen to the slits.
We also know that, 
or
where,
c is the speed of light
is frequency
is wavelength
So, equation (1) turns into
So,
or
Higher frequencies have larger spaces between line.
So, correct option is (C).
A hydrogen atom is an atom of the chemical element hydrogen. The electrically neutral atom contains a single positively charged proton and a single negatively charged electron bound to the nucleus by the Coulomb force. Atomic hydrogen constitutes about 75% of the baryonic mass of the universe.
Answer: A different group of scientists using different methods.
