Question

Study the information below and answer the questions that follow. The letters do not represent the actual symbols of the elements.

Element	Electronic  Configuration	Ionization energy KJ/mol
		1st I.E	2nd I.E.
X	2.2	900	1800
Y	2.8.2	736	1450
Z	2.8.8.2	590	1150

1. What chemical family does the elements X, Y and Z belongs? 
2. What is ionization energy?
3. The 2nd ionization energy is higher than the 1st ionization energy of each element. Explain. 
4. When a piece of element Z is placed in cold water, it sinks to the bottom and effervescence of a colourless gas that burns explosively is produced. Use a simple diagram to illustrate how this gas can be collected during this experiment.

Answer 1

1. What chemical family does the elements X, Y and Z belongs? 
   • Alkaline – earth metals
2. What is ionization energy? 
   • The amount of energy required to remove an electron from an atom when in gaseous state.
3. The 2nd ionization energy is higher than the 1st ionization energy of each element. Explain. 
   • 2nd ionization energy involves removal of an electron from a positively charged ion while 1st ionization energy involves removal of an electron from a neutral atom.
4.