An aluminium alloy plate 0.2m2 surface area (both sides), 4 mm thick and at z00 °c is suddenly quenched into liquid oxygen which is at -183 °c. find the time required for the plate to reach the temperature of -70 °c. take p-2700 kg/m3, c 890 j/kg °c, h=370 w/m2°c).

Atoms contain subatomic particles called protons and neutrons. when these protons and neutrons spilt, a lot of energy is released

One student said that the investigation was not valid (a fair test). write a plan for the investigation that includes improvements to the method and apparatus

Examine the false statement. compounds are the smallest unit of an element that occur most commonly in nature. select the rewording of the statement that is true. a: atoms are the smallest unit of an element that commonly occur in nature. b: molecules are the smallest unit of an element or compound that commonly occur in nature. c: molecules are the smallest unit of a compound that occur on the periodic table. d: compounds are the smallest unit of an element that occur on the periodic table