Question

The table below gives the number of electrons, protons and neutrons in substances X, Y and Z. Study it and answers the questions that follow.

Substance	Electrons	Protons	Neutrons
X	10	10	10
Y	10	8	10
Z	8	8	8

1. Which letter represents an ion? 
2. Which of the substances are isotopes? Give a reason. 
3. Show the electron arrangement of Y 

Answer 1

1. Y
2. Y and Z - Has the same number of protons but different number of Neutrons
3.  

   Substance	Electrons	Protons	Neutrons
   X	10  2:8:2	10	10
   Y	10  2:8:2	8	10
   Z	8  2:6	8	8

   2:8:2