Chemical hand warmers popular with skiers and snowboarders produce heat when they are removed from their airtight plastic wrappers. they utilize the oxidation of iron to form iron(iii) oxide according to the reaction:

the correct option is c.

isotopes refers to different forms of the same element with the same atomic number but different mass number as a result of difference in their neutron numbers. isotopes have different relative atomic mass but share the same chemical properties.

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.

the dissolution of polymer can be thermodynamically described in 2 steps.

water and alcohols have similar properties because water molecules contain hydroxyl groups that can form hydrogen bonds with other water molecules and with alcohol molecules, and likewise alcohol molecules can form hydrogen bonds with other alcohol molecules as well as with water.