Workers who build railway tracks often use a process called thermite welding to connect pieces of track. Thermite is a mixture of aluminum metal (Al) and ferric oxide (Fe2O3). A worker places thermite between two pieces of track and then burns it to form aluminum oxide (Al2O3) and iron (Fe). As the reaction happens, the air around the mixture becomes so hot that the two pieces of track fuse together. Is this chemical exothermic or endothermic?

Which statement correctly describes potassium iodide, ki? there is a one-to-one ratio of potassium ions to iodide ions. potassium gains electrons and iodine loses electrons during the reaction. the lattice is held together by potassium anions and iodide cations.

Apiece of metal with a length of 1.42 cm was measured using four different instruments. which of the following measurements is the most accurate?

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.