Question

The table below shows some properties and electronic arrangements of common ions of elements represented by letters P to X. Study the information in the table and answer the questions that follow

Element	Ion	Electron arrangement	Atomic radius	Ionic radius
P	P2+	2,8,8	0.197	0.099
Q	Q-	2,8	0.072	0.136
R	R+	2,8,8	0.231	0.133
S	S3+	2,8	0.143	0.050
T	T2+	2,8,8	0.133	0.074
U	U2+	2,8	0.160	0.065
V	V+	2,8	0.186	0.095
W	W+	2	0.152	0.060
X	X-	2,8,8	0.099	0.181

1. Give the atomic numbers of the elements P and Q 
2. Select the most reactive metallic element 
3. Select 3 elements that belong to the same group of periodic table
4. Select 3 elements that would react with cold water to evolve hydrogen gas
5. Why is the ionic radius of element X larger than its atomic radius?
6. Write an equation of the reaction between element S and Oxygen 

Answer 1

1. P - 20 
   Q –9 
2. R
3. P,T,U  
4. P, R, T, U, V
5.    
   • Form ions by gaining electrons  
   •  Since it is a non-metal/resulting in electron-electron ½mk  repulsion
6. 4S + 3O₂ → 2S₂O₃