Which of the following is TRUE regarding allotropes?
◦ Allotropes are different elements with the same structure and have different standard molar enthalpies.
◦ Allotropes are composed of different isotopes of the same element and have different standard molar enthalpies.
◦ Allotropes are different forms of the same element, but they have identical standard molar enthalpies.
◦ Allotropes are different forms of the same element and have different standard molar enthalpies.
◦ Allotropes are composed of different isotopes of the same element and identical standard molar enthalpies.