Answer is: 1s22s22p5.
1) Electron configuration 1s²1p⁶2d², this is not reasonable because 1p and 2d oritals do not exist.
2) Electron configuration 1s²2s⁴2p⁶, this is not reasonable because s orbitals only contain 2 electrons.
3) Electron configuration 1s²2s²2p⁵ is of an element fluorine. Fluorine (F) has atomic number 9, which means it has 9 protons and 9 electrons.
4) Electron configuration 1s²2s²2d⁶, this is not reasonable because 2d orbitals do not exist.
PbO2
You have to take the mass of lead in the problem, and divide by the molar mass.
When you do the same with oxygen, you get a number about twice as large as when you divide the mass of lead by the molar mass of lead. This means that the simplest formula would be PbO2
Answer:2
Explanation:
Ba(OH)2 contains two oxygen atoms
BaSO4 contains four oxygen atoms.
This means that barium sulphate contains two more oxygen atoms than barium hydroxide in its formula. This is clearly seen from the two formulae shown above.
<u>Answer:</u> The products of the reaction will be 
<u>Explanation:</u>
Single displacement reaction is defined as the reaction in which more reactive element displaces a less reactive element from its chemical reaction.
The general chemical equation for the single displacement reaction follows:

The given chemical equation follows:

Bromine element is more reactive than iodine element. Thus, can easily replace iodine from its chemical reaction.
Hence, the products of the reaction will be 