Classify the same processes as exothermic or endothermic.
Evaporation of alcohol from skin: liquid C3H30 +5.2 kJ → vaporized C3H30
Burning of propane in a gas grill: C3H8 +502 — 3C02 + 4H20 + 1652 kJ
Oxidation of iron to form rust 4Fe +30, 2Fe2O3 +2221 kJ

1. Endothermic

2. Exothermic

3. Exothermic

Crystal habit and cleavage.

Explanation:

When two physical properties of minerals both bring about smooth, flat surfaces that has specific angles between them.such that the first property is externally visible and is the result of how the mineral forms while the second property is internal and is the result of breaking a sample of the mineral, it should be noted that the properties are refered to as the crystal habit and cleavage.

It should be noted that the cleavage refers to the tendency of crystalline materials to be able to split along the structural planes.