Answer:
B. Ca(NO2)2
Explanation:
Ions (charged atoms) combine with one another to form stable ionic compounds. In this case, calicium ion (Ca2+) is said to react with NO2, which has a charge of -1 i.e. +1-1(2) = 1-2 = -1.
This means that calcium has a charge of +2 while nitrite ion has charge of -1, hence, when they combine, they exchange their charges, which become their subscript as follows:
Ca2+ + NO2- → Ca(NO2)2
Ca(NO2)2 is a stable ionic compound called calcium nitrite. Notice that it takes two atoms of NO2- to react with one atom of Ca2+.
is aluminium oxide (also called aloxide, aloxite and alundum). It is neither acid nor base. It has amphoteric nature meaning it can act as an acid with bases and as a base with acids. It neutralises them to salts.
The first shell can hold up to 2 electrons, the second shell can hold up to 8 (2 + 6) electrons, the third shell can hold up to 18 (2 + 6 + 10) and so on.
One mole of water weighs 18 grams. H₂O is composed of 2H= 2 and 1 0=16 adding gives you 18. number of moles= mass/ Relative Molecular Mass
Therefore, mass= Relative Molecular Mass×number of moles
= 18×5 moles
= 90 grams
