Some metals are found as uncombined elements, but most metals are extracted from ores found in
the Earth's crust. Different metals are extracted
using different methods.
Explain how the method used to obtain a metal is
related to its position in the reactivity series and to
the cost of the extraction process. In your answer,
refer to aluminium, iron and gold as examples.
(6 marks)

Use examples from the article to explain one positive and one negative effect that chemistry has had on society.

The content of manganese (mn) in steel was determined spectrophotometrically and with the use of the standard addition method. an unknown sample of mn from a digested steel sample gave an absorbance of 0.185 when analyzed spectrophotometrically. when 5.00 ml of solution containing 95.5 ppm mn was added to 50.0 ml of the unknown steel solution (digested sample), the absorbance was 0.248. calculate the concentration, in parts-per-million (ppm), of mn in the digested steel sample solution.

Categorize them by metal, nonmetal, in periodic tableductilenon-ductilemalleableoft en gain electrons easilygood conductorpoor conductorcan be liquidselements