The whitening toothpastes showed differences in their physical-chemical properties. All toothpastes promoted changes to the surface, probably by the use of a bleaching agent.
The statement which best describes the development of theories that connected microscopic and macroscopic phenomena is; <em>q</em><em>It took several hundred years for scientists to develop current theories, and they are still being revised to </em><em>this.</em>
<em>Discussion</em><em>;</em>
Most scientific theories involving microscopic and macroscopic phenomenon have taken several years to be developed; however, this theories are still under revision till date.
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Answer:
4 shared electrons
Explanation:
There are 4 shared electrons in the lewis structure of h2o2.
A mixture of hydrogen and oxygen would not need to have a certain ratio of hydrogen atoms to oxygen atoms to differ from the compound known as water.
<h3>Why is water a compound not a mixture?</h3>
A water molecule has 2 hydrogen atoms bonded chemically to oxygen atoms and has the formula H₂O.
In a chemical reaction, two atoms react together chemically to form a new product which means the reactants lose their individual properties and obtain new properties of the product formed.
Hence, water is a compound as hydrogen and oxygen atoms are bonded chemically to each other.
On the other hand, if oxygen and hydrogen form a mixture which is a physical change then they retain their individual properties in the mixture. They do not need to be in a specific ratio and there are no chemical changes taking place.
Chemical change determines if a substance is a mixture or a compound.
Thus, a mixture of hydrogen and oxygen is different from water if it doesn't have a certain ratio of hydrogen atoms to oxygen atoms.
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B. Folds
Hope that helps! :)
