A. hydroxide is the answer
Answer:
Option D = No, when elements combine to form a new material, they have properties unique to the new materials.
Explanation:
When sodium contact with water it loses its one electron and thus gain positive charge. When there are more sodium atoms present and many atoms do this thus more positive ions are produced and these positive ions repeal each other at high speed and explosion occur.
But when it form compound with other material, it will not showed this behavior.
Example:
Consider the sodium chloride, when it dissolve in water sodium not showed explosion. In sodium chloride sodium already gives its electron to the chlorine and have stable electronic configuration. The sodium present in cationic form. When it dissolve, partial positive charge of water surrounds the Cl⁻ and partial negative charge of water surrounds the Na⁺ ion, ans sodium chloride gets dissolve into water without explosion.
Answer: For the elementary reaction 
the molecularity of the reaction is 2, and the rate law is rate = ![k[NO_3]^1[CO]^1](https://tex.z-dn.net/?f=k%5BNO_3%5D%5E1%5BCO%5D%5E1)
Explanation:
Order of the reaction is defined as the sum of the concentration of terms on which the rate of the reaction actually depends. It is the sum of the exponents of the molar concentration in the rate law expression.
Elementary reactions are defined as the reactions for which the order of the reaction is same as its molecularity and order with respect to each reactant is equal to its stoichiometric coefficient as represented in the balanced chemical reaction.
Molecularity of the reaction is defined as the number of atoms, ions or molecules that must colloid with one another simultaneously so as to result into a chemical reaction. Thus it can never be fractional.
For elementary reaction , molecularity is 2 and rate law is ![rate=k[NO_3]^1[CO]^1](https://tex.z-dn.net/?f=rate%3Dk%5BNO_3%5D%5E1%5BCO%5D%5E1)
In the modern periodic table when elements are arranged according to their atomic number.
