<span>From the above given choices :
melting is an endothermic process</span>
Shielding electrons are the electrons in the energy levels between the nucleus and the valence electrons. They are called "shielding" electrons because they "shield" the valence electrons from the force of attraction exerted by the positive charge in the nucleus. Hope this helps!!
In a neutral ionic compound, you can determine its sub-scripts by simply flipping the ionic charges and dropping the signs: so AlS would be Al2S3
