D. The number of electrons equals the atomic number for a neutral element. Each number after the letter refers to the number of electrons in that shell. So for D, 2+2+6+2+6+2 = 20 electrons, which is equal to the atomic number.
Electrons can gain the energy it needs by absorbing light. If the electron jumps from the second energy level down to the first energy level, it must give off some energy by emitting light. The atom absorbs or emits light in discrete packets called photons, and each photon has a definite energy.
Reaction won't occur
Because the activity of Cu is less than Al
If it is assumed that there are only two isotopes then the percent abundance needs to add up to 100%
100-35= 65%
The second isotope will have a 65% abundance.
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number 5 is 1 : 1
number1 is also 1:1 ibelieve but it could be 2:1 just like number 5 but im postive its 1:1 for nummer 1 and number 5