Thru ionic bonding. The oppositely charged ions attract each other so ionic bond forms. Ionic bonding occurs when a metal bonds with a non-metal.
The cooling effect meaning that your skin releases alcohol molecules with the appropriate heat for it to evaporate. The alcohol is cold on your skin for the reason that when it comes in contact, the temperature of the body makes it change from fluid to gas, which pulls warm from the encompassing condition, including the skin. The aftereffect of this response is a chilly feeling.
<span>Describe the changes in the atomic model over time.
The existence of atoms began to be accepted around 1910 when many theories called upon the fact that atoms most exist (for example the work of Boltzmann trying to explain entropy, died 1906).
</span>At that time atoms were seen as tiny small ball like objects, all matter was composed of. the models have been advanced ever since. Key names that are worth looking up are J. J. Thomson, Rutherford, Bohr and de Broglie.
Explain how different observations and experiments led to changes in the atomic model.
Many of the models that the men above proposed were created upon what they saw from their experiments. An example is that Niels Bohr wanted to explain the spectral lines in hydrogen, introducing the energy shells are quantized.
de Broglie saw that we could calculate wavelengths for particles with a certain velocity, introducing the particle wave duality.
Rutherford suggested that electrons are orbiting the nucleus like planets.
Thomson that there was a "electronsness" surrounding a positive core.
They can all be explain more deeply, but this is just introductory.
Answer:
3.76 g of O₂ are needed to produced 12.5 g of Fe₂O₃
Explanation:
The reaction is: 4Fe (s) + 3O₂ (g) → 2Fe₂O₃ (s)
4 moles of iron react to 3 moles of oxygen in order to produce 2 moles of iron (III) oxide.
Let's determine the moles of the produced product.
12.5 g . 1mol/ 159.69g = 0.0783 moles
If we assume Iron in excess, we work with the oxygen.
2 moles of Fe₂O₃ are produced by 3 moles of oxygen
Then, 0.0783 moles of Fe₂O₃ might be produced by (0.0783 . 3)/2
0.117 moles.
We convert the moles to mass → 0.117 mol . 32 g/1mol = 3.76 g
