It is fresher because of new transportation techniques and refrigerated trailers.
Answer:
(i) Electric Wires - Tin
(ii) Ornaments - Gold
(iii) Filament of bulb - Tungsten
(iv) Silvery Foil over sweets - Silver
(v) Foils to wrap food - aluminum
(vi) Pipes to supply water - Plastic or PVC pipes
The heat of the reaction is an extensive property: it is proportional to the quantity of the quantity that reacts.
The change in enthalpy is a measured of the heat evolved of absorbed.
When the heat is released, the change in enthalpy is negative.
The reaction of 2 moles of Na develops 368.4 kj of energy.
Calculate the number of moles of Na in 1.90 g to find the heat released when this quantity reacts.
Atomic mass of Na: 23 g/mol
#mol Na = 1.90 g / 23 g/mol = 0.0826 mol
Do the ratios: [368.4 kj/2mol ] * 0.0826 mol = 15.21 kj.
Then the answer is that 15.21 kj of heat is released (evolved)
They do not move they stay in the same same place it may look like they move because of the earth rotation
