Photon has no mass at all
The highest atom economy
2CO + O₂ ⇒ 2CO₂
<h3>Further explanation</h3>
Given
The reaction for the production of CO₂
Required
The highest atom economy
Solution
In reactions, there are sometimes unwanted products that can be said to be a by-product or a waste product. Meanwhile, the desired product can be said to be a useful product, which can be shown as the atom economy
of the reaction
the higher the atomic economy value of a reaction, the smaller the waste/ byproducts produced, so that less energy is wasted
The general formula:
Atom economy = (mass of useful product : mass of all reactants/products) x 100
<em>or
</em>
Atom economy = (total formula masses of useful product : total formula masses of all reactants/products) x 100
So a reaction that only produces one product will have the highest atomic value, namely the reaction in option C
Ionic compounds are formed between oppositely charged ions.
A binary ionic compound is composed of ions of two different elements - one of which is a positive ion(metal), and the other is negative ion (nonmetal).
To write the empirical formula of binary ionic compound we must remember that one ion should be positive and other ion should be negative, then only the correct formula should be written. To write the empirical formula the charges of opposite ions should be criss-crossed.
First empirical formula of binary ionic compound is written between
First Formula would be 
Second empirical formula is between 
Second Formula would be 
Note : When the subscript are same they get cancel out, so 
would be written as 
Third empirical formula is between 
Third Formula would be :
Forth empirical formula is between 
Forth Formula would be : 
or 
Note- The subscript will be simplified and the formula will be written as .
The empirical formula of four binary ionic compounds are : 
Answer:
Cultural Pest Control.
Explanation:
The cultural pest control is one of the oldest methos of pest control. This form of pest control is less practiced these days since curative form of pest control methods have been invented. The cultural pest control method is a preventive method of managing pest population. This pest control method takes long days of planning and execution.
<u>In this form of pest control method, the farmer had to change the timings of his farming operations in his field. This method requires careful timing in seeding and planting. This method of pest controlling requires knowledge and skills of fields</u>.
Thus the correct answer is the third option.
