Answer is periodic because only happens in certain times
Formula: NA2S2O3. Valency: 2
I think that type of rock is call Igneous rock because the igneous rock is molten rock from volcanoes.
Answer:
Electrons in a hydrogen atom must be in one of the allowed energy levels. If an electron is in the first energy level, it must have exactly -13.6 eV of energy.
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Energy Levels of Electrons.
Energy Level Energy
1 -13.6 eV
2 -3.4 eV
3 -1.51 eV
4 -.85 eV