Answer:
Modern periodic law
Explanation:
There are many ways of stating the modern periodic law. Generally, the modern periodic law states that the properties of elements are a periodic function of their atomic numbers. That means, similar properties recur periodically when elements are arranged according to increasing atomic number.
Two scientists were largely responsible for our present day understanding of the modern periodic law, they are, Mendeleev and Moseley. Their work laid the foundation for the periodic table in its current form.
Answer:
The answer is "
".
Explanation:
Please finds the complete question in the attached file.


The mass of acetone to be weighed is 
Answer:
The reactivity of metal is determined by the reactivity series. ... The metal which easily displaced aluminium will lie above in the series but that same element cannot displace sodium, so it will lie below in the series. Hence, from the series, we conclude that the unknown metal could be calcium or magnesium.
Explanation:
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Your question looks a bit incomplete as you have the same contents in options a) and d). According to your list, I can't see the correct answer, but I can give you one.The difference between the potential energy of the products of the potential energy of the reactants is equal to the enthalpy of the reaction.