Why is specific heat an intensive property?
Because of the definition of intensive .
An intensive property is one which does not change if you increase or decrease the amount of the matter present. Color is such a property. Black paint is black whether you have a lot of it or a small amount of it.
The heat added to an object is related to the resulting temperature change and its mass by the formula
Specific heat is the character
Assume you have 2 samples of copper, one 2X the mass of the other. You control the amount of heat applied,
I hope this helps,