The season that is starting is winter.
The answer to 21 is (4)
The formation of Fossil Fuels.
The fossil fuels such as oil originate mostly from aquatic organism and are extracted on oil rigs located in oceans and seas. Most of the oil is procured this way.
The balanced chemical reaction would be
<span>fecl2 + 2naoh = fe(oh)2(s) + 2nacl
Initial amounts of the reactants are given, so, we need to determine which of the reactants is the limiting reactant and use this amount to determine what is asked. However, what is being asked is how many of the FeCl2 is used in the reaction, showing that it is NaOH that is the limiting reactants. Thus, we just use the initial amount of NaOH and relate the substances by the chemical reaction as follows:
6 mol NaOH ( 1 mol FeCl2 / 2 mol NaOH ) = 3 mol FeCl2
Therefore, 3 moles of FeCl2 is used up and 3 moles of FeCl2 is also left after the reaction.</span>
Taking into account the scientific notation, the result of the subtraction is 6.5×10⁵.
<h3>Scientific notation</h3>
First, remember that scientific notation is a quick way to represent a number using powers of base ten.
The numbers are written as a product:
a×10ⁿ
where:
- a is a real number greater than or equal to 1 and less than 10, to which a decimal point is added after the first digit if it is a non-integer number.
- n is an integer, which is called an exponent or an order of magnitude. Represents the number of times the comma is shifted. It is always an integer, positive if it is shifted to the left, negative if it is shifted to the right.
<h3 /><h3>Subtraction in scientific notation</h3>
You want to subtract two numbers in scientific notation. It should be noted that when the numbers to be added do not have the same base 10 exponent, the base 10 power with the highest exponent must be found. In this case, the highest exponent is 5.
Then all the values are expressed as a function of the base 10 exponent with the highest exponent. In this case: 5.00×10⁴=0.500×10⁵
Taking the quantities to the same exponent, all you have to do is subtract what was previously called the number "a". In this case:
7.00×10⁵ - 0.500×10⁵= (7.00- 0.500)×10⁵= 6.5×10⁵
Finally, the result of the subtraction is 6.5×10⁵.
Learn more about scientific notation:
brainly.com/question/11403716
brainly.com/question/853571
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Unsaturated organic compounds with a carbon-to-carbon double bond and alkynes with a carbon-to-carbon triple bond, as well as aldehydes and ketones with a carbon-to-oxygen double bond, undergo addition reactions.
