Which one of the following is most abundant in earth crust?

Copper is extracted from

Which of the following benefaction processes is used for the mineral,Al₂O₃.2H₂O?

Name two metals which occur in nature as oxides.

What criterion is followed for the selection of the stationary phase in chromatography?

Name one chief ore each of copper and aluminium. Name the method used for the concentration of these two ores.

State the role of 
(i) depressant in froth floatation process.
(ii) silica in the metallurgy of copper.
(iii) graphite rod in the electrolytic reduction of alumina.

What are the terms flux and slag? Explain the different types of fluxes used.

While washing a miner's overalls, a washer woman noticed that sand and similar dirt fell to the bottom of the wash tub. What was peculiar, the copper bearing compounds that had come to the clothes from the mines were caught in the soaplids and so they came to the top. One of her clients was a chemist, Mrs. Malik. The washer woman told her experience to Mrs. Malik. The latter thought that the idea could be used for separating copper compounds from rocky and earth materials on a large scale. After reading the above passage answer the following questions-
What values are shown by washer woman and Mrs.Malik?

Metals are very useful in our daily life. Aluminium powder is used in white paints. It is also used as a reducing agent. Alloys containing aluminium being light, are very useful. Utensils of aluminium are more popular than utensils of brass. Metals like silver, gold, iron, copper, zinc are very useful in our daily life.
What value is associated for using aluminium?