Lesson 599 of 1524
Atomic Physics
The first direct observation of atoms was in Brownian motion
Practice this chapterThe first direct observation of atoms was in Brownian motion Analysis of Brownian motion gave accurate sizes for atoms ( 10 -10 m on average) and a precise value for Avogadro’s number
The planetary model of the atom pictures electrons orbiting the nucleus in the same way that planets orbit the sun The planetary model of the atom pictures electrons orbiting the nucleus in the way that planets orbit the sun.
atom — basic unit of matter, which consists of a central, positively charged nucleus surrounded by negatively charged electrons. positive charge in the nuclei — carried by particles called protons, which have a charge-to-mass ratio of q p m p = 9. Brownian motion — the continuous random movement of particles of matter suspended in a liquid or gas. planetary model of the atom — the most familiar model or illustration of the structure of the atom.
Worked example
What does “atom” mean in Atomic Physics?
- 1Use the wording this chapter gives for atom.
- 2The book says: basic unit of matter, which consists of a central, positively charged nucleus surrounded by negatively charged electrons.
- 3Do not use the meaning of positive charge in the nuclei. That term means carried by particles called protons, which have a charge-to-mass ratio of q p m p = 9.
Result: basic unit of matter, which consists of a central, positively charged nucleus surrounded by negatively charged electrons
Why. That is the meaning this chapter gives for atom.
Do not swap atom and positive charge in the nuclei. atom means basic unit of matter, which consists of a central, positively charged nucleus surrounded by negatively charged electrons. positive charge in the nuclei means carried by particles called protons, which have a charge-to-mass ratio of q p m p = 9.
Practice margin
This chapter
A fresh set from this chapter only. Choose 10 or 20. Multiple choice and fill-in, with no repeat inside the set.