Aluminum is a silvery white light metal. It has plasticity. Commodities are often made into columns, rods, sheets, foils, powders, ribbons and filaments. An oxide film can be formed in humid air to prevent metal corrosion. Aluminum powder treated with acid will burn violently when heated in air, giving off a dazzling white flame. Soluble in dilute sulfuric acid, dilute nitric acid, hydrochloric acid, sodium hydroxide and potassium hydroxide solution, insoluble in water, but can slowly react with hot water to generate aluminum hydroxide, with a density of 2700 kg/m3, an elastic modulus of 70Gpa and a Poisson's ratio of 0.33. The melting point is 660℃. The boiling point is 2327℃. It is widely used because of its light weight, good electrical and thermal conductivity, high reflectivity and oxidation resistance. Aluminum used in daily utensils is usually called "steel refined" or "steel grade".
Aluminum is an active metal. In dry air, a dense oxide film with a thickness of about 50 angstroms is immediately formed on the surface of aluminum, so that aluminum will not be further oxidized and can be waterproof. But aluminum powder is very flammable when mixed with air; Molten aluminum can react violently with water to produce corresponding metal oxides; Aluminum is amphoteric and soluble in strong alkali and dilute acid, but cold concentrated nitric acid and concentrated sulfuric acid will passivate aluminum.
Aluminum can also react with water. Water is a very weak electrolyte, but it can weakly ionize hydrogen ions and hydroxide ions to react with aluminum to generate aluminum hydroxide and hydrogen. The reaction conditions can be heated or carried out at room temperature, which is difficult to observe. According to the reducibility of aluminum, it can be inferred that aluminum can react with water, but it is found that aluminum hardly reacts with boiling water. Aluminum can obviously react with water vapor under heating conditions, but from the beginning of the reaction, it forms a dense oxide film with oxygen in water, which prevents further reaction.
The vowel letter u is pronounced with the long vowel /u/ in the stressed opening syllable. Pronunciation of the tongue is backward, which is the highest of the five post vowels. The gums are nearly complete, and the lips are small and round, but there is no friction. This sound mainly appears after /j/, in the middle and at the end of the word, and rarely appears at the beginning of the word. For example:
Prosecute
Blue blue
Glue glue
I hope it can help you solve the problem.