Electron density is the measure of theprobability of an electron being present at a specific location.
In molecules, regions of electron density are usually found around the atom, and its bonds. In de-localized orconjugated systems, such as phenol,benzene and compounds such as hemoglobin and chlorophyll, the electron density covers an entire region, i.e., in benzene they are found above and below the planar ring. This is sometimes shown diagrammatically as a series of alternating single and double bonds. In the case of phenol and benzene, a circle inside a hexagon shows the de-localized nature of the compound.
Answer : The speed in miles per hour is 22 mile/hr.
The speed in yard per min is 26617.8 yard/min
Explanation :
The conversion used for meters to miles is:
The conversion used for second to hour is:
The conversion used for meter per second to mile per hour is:
As we are given the speed of 407.0 meter per second. Now we have to determine the speed in miles per hour.
So, 
Therefore, the speed in miles per hour is 22 mile/hr.
The conversion used for meter to yard
1m = 1.09 yard
The conversion used for second to hour is:
The conversion used for meter per second to mile per hour is:
As we are given the speed of 407.0 meter per second. Now we have to determine the speed in yards per min
So, 
Therefore, the speed in yard per min is 26617.8 yard/min
Answer:
option B is correct.
Y is a mixture in the picture.
Explanation:
Different types of substances combine physically and form a mixture.
Mixture formed by the combination of two or more substances that that combine in same physical state.
For example mixture of copper sulphate and solid chloride in dry form and that will look like white and blue crystal in a mixture.
The picture Z showing dots of same color and is not a mixture, while picture Y shows dots of different colors clearly indicating that it is picture for mixture.
Answer:
Cracking.
Explanation:
A chemical reaction can be defined as a reaction in which two or more atoms of a chemical element react to form a chemical compound. An example of a chemical reaction involving hydrocarbons is cracking.
Hydrocarbon can be defined as an organic compound that comprises of hydrogen and carbon only.
In Organic chemistry, cracking refers to the process of lowering the boiling point of a heavy, complex or long-chain hydrocarbon such as kerogens by exposing it to different environmental treatments such as hydrogen enriched catalysts, pressure or high temperatures, in order to produce smaller, lighter and more useful molecules (alkanes and alkenes) such as gasoline, diesel fuel, etc.
