Cho 3,9g kim loại kiềm tác dung vs nước ( dư ) thu được 1,12 lít khí hidro ( đktc ) và dung dịch A Xác định tên kim loại
Tính thể tích dung dịch HCL 1M cần để trung hòa dung dịch A

Athin, square metal plate measures 14 cm on each side and has emissivity of 0.60. the plate is heated to a temperature of 745°c. what is the rate at which the plate radiates energy ? the stefan-boltzmann constant is 5.67 × 10-8 w/(m2 ? k4). remember that the plate will radiate energy from both its top and bottom surfaces.

Suppose that a comet that was seen in 563 a.d. by chinese astronomers was spotted again in year 1951. assume the time between observations is the period of the comet and take its eccentricity as 0.986. what are (a) the semimajor axis of the comet's orbit and (b) its greatest distance from the sun?

Why don't you see your reflection in water with waves or repples