Answer:
Niels Bohr, refined the model of an atom by proposing a quantized shell structure atomic model in order to describe how the electrons are able to maintain stable orbits around the nucleus
Based on the predictions of classical mechanics the electron motion of the Rutherford model was unstable as the electrons where expected to have lost some energy during motion and thus having to come rest in the nucleus
According to the modification by Neils Bohr in 1913, electrons move in shells or orbits of fixed energy and emission of electromagnetic radiation takes place only when electrons changes the orbit in which they move
Explanation:
<span>PbO
Let's look at each of the 4 compounds and see what's needed.
PbO.
* Oxygen has a valance shell that's missing 2 electrons and wants to get those 2 elections. Lead donates them, so you have a Lead (II) ions. This is a correct choice.
PbCl4
* Chlorine wants to grab 1 electron to fill it's valance shell and Lead donates that election. However, there's 4 chlorine atoms and every one of them wants and electron, and lead is donating all 4 of the desired electrons making the Lead (IV) ion. So this is a bad choice.
Pb2O
* Oxygen still wants 2 electrons and gets them from the lead. But there's 2 lead atoms and each of them donates 1 election making for 2 Lead(I) ions. So this too is a bad choice.
Pb2S
* Sulfur is in the same column of the periodic table as oxygen and if this compound were to exist would have similar properties as Pb2O and would have Lead(I) ions. So this is a bad choice.</span>
Answer:

Explanation:
Hello there!
In this case, it is possible to comprehend these mass-particles problems by means of the concept of mole, molar mass and the Avogadro's number because one mole of any substance has 6.022x10²³ particles and have a mass equal to the molar mass.
In such a way, for C₆H₁₂O₆, whose molar mass is about 180.16 g/mol, the referred mass would be:

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Polyethene is a polymer composed of repeating units of the monomer ethene.
The properties of polyethene are as follows:
- density- ranges 0.857 g/cm3 to 0.975 g/cm3.
- specific heat capacity is 1.9 kJ/kg.
- melting temperature is approximately 110 °C.
<h3>What are polymers?</h3>
Polymers are large macromolecules consisting of long repeating chains of smaller molecules known as monomers.
An example of a polymer is polyethene composed of repeating units of the monomer ethene.
The density of polyethylene ranges 0.857 g/cm3 to 0.975 g/cm3.
The specific heat capacity of polyethene is 1.9 kJ/kg.
The melting temperature of polyethene is approximately 110 °C.
Learn more about polyethene at: brainly.com/question/165779
Answer:
B
Explanation:
B is the best showing of a chemical reaction out of the choices