Question

Show the compound formation of Magnesium Oxide with the help of a neat diagram (Magnesium- atomic number 12, Oxygen- atomic number 8). Platinum (78Pt175) undergoes alpha decay to form a new element Osmium (ZOsA ). Find the mass number (A) and atomic number (Z) of Osmium. 78Pt175 ZOsA + 2He

Answer 1

Answer: 1. $MgO$

2. mass number of osmium = 171

Atomic number of osmium = 76

Explanation:

1. For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.

Here magnesium is having an oxidation state of +2 called as $Mg^{2+}$ cation and oxide $O^{2-}$ is an anion with oxidation state of -2. Thus they combine and their oxidation states are exchanged and written in simplest whole number ratios to give neutral $MgO$.

2. Alpha decay : When a larger nuclei decays into smaller nuclei by releasing alpha particle. In this process, the mass number and atomic number is reduced by 4 and 2 units respectively.

General representation of an element is given as:   $_Z^A\textrm{X}$

where,

Z represents Atomic number

A represents Mass number

X represents the symbol of an element

General representation of alpha decay :

$_Z^A\textrm{X}\rightarrow _{Z-2}^{A-4}Y+_2^4\alpha$

$_{78}^{175}\textrm{Pt}\rightarrow_{76}^{171}\textrm{Os}+_2^4\textrm{He}$

Thus atomic number of osmium is 76 and mass number of osmium is 171.