Aluminum
Bauxite ore is the world's primary source of aluminum. The ore must first be chemically processed to produce alumina (aluminum oxide). Alumina is then smelted using an electrolysis process to produce pure aluminum metal. Bauxite is typically found in topsoil located in various tropical and subtropical regions.
In the first situation: the mechanism of covection is the main form of heat transfer when warm air from a heater moves around and upward.
In the case of the metal pan the mechanism of heat transfer is conduction.
In the case of sunburn the mechanism is radiation.
In the case of an ice cube melting in a hand, conduction is the most important mechanism.
The solution is an alkali.
Usually with the pH value range of 14, substances with pH 7 can be called neutral. Meanwhile substances lower than pH 7 are acids, the lower the pH is, the more acidic it is. Such as cola, it has a pH 2, which is very acidic.
In opposite, the substances with pH over 7 are called alkalis. Again, the larger the pH value is, the more alkaline it is. So pH 13 is a strong alkaline therefore it it corrosive and can clean the toilet well.
Scientific investigation is the process in which scientist solve the problems by using different systematic approach. It can be initiated in different ways.
Experimental Scientific investigation: The investigation in which scientist answer the question on the basis of experimental results. Experimental investigation contains both dependent and independent variables, and only one variable is tested at a time is possible. This process makes uses of collecting observation and identifying the process in physical word.
Noting the colour of a solution when heated is the experimental scientific investigation
Therefore, other given options are part of scientific observation whereas Noting the colour of a solution when heated explains the experimental scientific investigation.