- Electrons are the negatively charged sub-atomic particles of an atom.
- The mass of an electron is considered to be negligible, and its charge is -1.
- The symbol for an electron is e–
- Electrons are extremely small.
- They are found outside the nucleus.
Thomson’s model of an atom
- According to Thomson,(i) An atom consists of a positively charged sphere and the electrons are embedded in it. (ii) The negative and positive charges are equal in magnitude. So, the atom as a whole is electrically neutral
- The first model of an atom to be put forward and taken into consideration.
- He proposed a model of the atom be similar to that of a Christmas pudding/watermelon.
- The red edible part of the watermelon is compared with the positive charge in the atom.
- The black seeds in the watermelon are compared with the electrons which are embedded on it.