I think the element that has been correctly defined by Antoine Lavoisier would be the element oxygen. He is famous for the discovery of the importance of the molecule oxygen in the process of combustion. He is is the one who characterized and named the element oxygen and hydrogen. Also, showing how these atoms combine in order to form a water molecule in the combustion process. He is considered as the father of modern chemistry as he helped in organizing nomenclature of the chemical compounds. He also is responsible for laying the foundations of the famous law of conservation of mass.
You can't calculate the electronegativity difference of a single molecule you'll need a frame of reference to explain the electronegativity difference and properties arising due to the difference. Another term arise here is modified electronegativity that is calculated within the molecule between two atoms of different electronegativity and use to explain the nature of molecule wether they are electron withdrawing group or electron donating group and also used to compare the electronegativity with other molecule!
It means there is a lot of the same thing and not many others
Answer: ammonium bromide : acidic : The pH will be less than 7.
potassium cyanide : basic :The pH will be more than 7.
calcium nitrate: neutral : The pH will be approximately equal to 7.
calcium hypochlorite : basic :The pH will be more than 7.
Explanation:
pH is defined as the negative logarithm of hydrogen ion concentration. The scale ranges from 0 to 14.
When a solution is acidic, it will show a pH in the range of 0 - 6.9. When a solution is basic, it will show a pH in the range of 7.1 - 14. When a solution is neutral, it will show a pH of 7.
ammonium bromide :
: acidic as it is formed from the combination of strong acid HBr and weak base 
potassium cyanide :
: basic, as it is formed from the combination of weak acid HCN and strong base KOH
calcium nitrate:
: neutral, as it is formed from the combination of strong acid and strong base.
calcium hypochlorite :
: basic, as it is formed from the combination of weak acid
and strong base 
The second law states that the acceleration of an object is dependent upon two variables - the net force acting upon the object and the mass of the object. F = ma; a = F/m. This means that Force over the mass. In order to improve the acceleration without redesigning is that the company has to improve the force assuming that the mass is still the same.