An atom usually contains three main particles. Complete the following table on your understanding of the chapter: Name of the particles Kind of charge each carries Mass relativity of H atom 1 2 3

Name of the particles Kind of charge each carries Mass relativity of H atom Protons positive charge 1 . 67 × 10 - 24 Neutrons Neutral charge 1 . 67 × 10 - 24 Electrons Negative chage 9 . 1 × 10 - 28

Complete the table below (where A, B, C and D are elements) given B is an inert gas (not helium though): Element Atomic number Number of electrons in outermost orbit A Z - 1 B Z C Z + 1 D Z + 4 Which of the elements A, B, C and D given above would you expect to be (i) Metallic (ii) Non-metallic

Element Atomic number Number of electrons in outermost orbit A Z - 1 7 electrons B Z 8 electrons C Z + 1 1 electrons D Z + 4 4 electrons The element C represents metallic element as it can easily lose its one outermost electrons to form positive ion. The elements A represents a non-metallic element. A can easily gain one electron to complete its octet. The element D can behave as a metal or a non-metal. Therefore, it is a metalloid.