Exercise 1. Fill in the blanks. (a) Dalton said that atoms could not be divided (b) An ion which has a positive charge is called a cation. (c) The outermost shell of an atom is known as valence shell. (d) The nucleus of an atom is very hard and dense. (e) Neutrons are neutral particles having mass equal to that of protons. (f) Isotopes are the atoms of an element having the same atomic number but a different mass number. 2. Write ‘true’ or ‘false’ for the following statements: (a) An atom on the whole has a positive charge. false (b) The maximum number of electrons in the first shell can be 8. false (c) The central pad of the atom is called nucleus. True. 3. Give the following a suitable word/phrase. (a) The sub-atomic particle with negative charge and negligible mass. (b) Protons and neutrons present in the nucleus. (c) The electrons present in the outermost shell. (d) Arrangement of electrons in the shells of an atom. (e) The number of protons pre...
You will find answers of ICSE Text Books here