How many elements are in Magnesium Silicate MgSiO4 (the 4 is small)

Which statement describes james chadwick’s discovery.

Asample of freon gas has a volume of 2.23 liters, a pressure of 4.85 kpa, and a temperature of -1.36°c. calculate the volume at a pressure of 1.38 kpa and a temperature of 5.5°c. (show work)

Ajet plane is speeding down the runway during takeoff. air resistance is not negligible. identify the forces on the jet.