1s²
Explanation:
The predicted electron configuration of Helium 1s².
Helium is an element with atomic number of 2. it is located on the last group on the periodic table.
- Electron distribution into the energy levels or sublevels of atoms can be shown using electronic configurations.
Here, the two electrons in Helium fills the first energy level with s-sublevel first.
The maximum number of electrons in the sub-level is 2: this gives the 1s² configuration.
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<span>2 KClO3(s) → 3 O2(g) + 2 KCl(s)
</span><span>Note: MnO2 (Manganese Dioxide) is not part of the reaction. A catalyst lowers the activation energy and increases both forward and reverse reactions at equal rates.
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molar mass of KClO3 = 122.5
Moles of KClO3 = 3.45 / 122.55 = 0.028
Moles of O2 produce =

= 0.042 moles
molar mass of O2 = 32
so, mass of O2 = 32 x 0.042 = 1.35 g
Answer:
Sirius B is primarily made out of a carbon-oxygen mixture that was generated by helium fusion in the progenitor star. The outer atmosphere is now almost pure hydrogen, the element with the lowest mass.
Explanation:
Answer:
Its right you dont have to change anything