Chapter 22 Molecular properties of gases
Chapter 22 Molecular properties of gases
22-1 The atomic nature of matter 物质的原 质 .J. Thomson discovered electrons in 1897 Rutherford discovered the nature of atomic nucleus He was at his lab at Mcgill Univ. in 1905
J. J. Thomson discovered electrons in 1897. 22-1 The atomic nature of matter (物质的原子本质) Rutherford discovered the nature of atomic nucleus. He was at his lab at McGill Univ. in 1905
1 Brownian motion The modern trail to belief in atoms can be said to have started in 1828 the observation of Brownian motion In 1828 Robert Brown observed through his microscope that tiny grains of pollen suspended in water underwent ceaseless random motion We now call this phenomenon“ Brownian motion” See动画库\力学夹\4-01布朗运动
In 1828 Robert Brown observed through his microscope that tiny grains of pollen suspended in water underwent ceaseless random motion. We now call this phenomenon “Brownian motion”. The modern trail to belief in atoms can be said to have started in 1828: the observation of Brownian motion. 1. Brownian motion See动画库\力学夹\4-01布朗运动
2. Properties of the ideal gas O The ideal gas consists of particles, which are in random motion and obey Newtons Laws of motion. These particles are"“ atoms”or“ molecules” ()The total number of particles is "large. The rate at which momentum is delivered to any area A of the container wall is essentially constant (I)The volume occupied by molecules is a negligibly small fraction of the volume occupied by the gas
(I) The ideal gas consists of particles, which are in random motion and obey Newton’s Laws of motion. These particles are “atoms” or “molecules”. (II) The total number of particles is “large”. The rate at which momentum is delivered to any area A of the container wall is essentially constant. (III) The volume occupied by molecules is a negligibly small fraction of the volume occupied by the gas. 2. Properties of the ideal gas
(M No forces act on a molecule except during a collision M All collisions are elastic and negligible duration Total kinetic energy of the molecules is a constant, and total potential energy is negligible
(IV) No forces act on a molecule except during a collision. (V) All collisions are elastic and negligible duration. Total kinetic energy of the molecules is a constant, and total potential energy is negligible