The elements on the periodic table are listed in increasing atomic number.
Hydrogen is the first element, and has an A.N. of 1. Also, its very interesting how it doesn't need 8 valence electrons to be stable.
The second element is Helium, which has an A.N (atomic number) of two.
Answer:
The options are unclear, however, the correct option is:
Aqueous solutions of ionic compounds cause to dissociate, hence, ions are free to conduct electricity
Explanation:
Ionic compounds are compounds formed from ions (charged atoms). For example, NaCl is an ionic compound from the following ions; Na+ (cation) and Cl- (anion). One characteristics of ionic compounds is their ability to dissociate into the ions that form them when in an aqueous solution i.e. NaCl will dissociate into Na+ and Cl- when in an aqueous solution.
These disssociated ions are free to conduct electricity, hence, making ionic compounds good conductors of electricity.
The oxidation number of H is -1.
Sum of the oxidation numbers in each element =
charge of the complex
CaH₂ has 1 Ca atom and 2H atoms. The charge of
the complex is zero. Let’s say Oxidation number of H is "a".
Then,
<span> (+2)
+ 2 x a = 0 </span>
<span> +2 + 2a = 0</span>
2a = -2
a = -1
Hence, the oxidation number of Hydrogen atom in CaH₂ is -1
