Which one of the following is a correct electronic configuration of sodium? (a) 2, 8 (b) 8, 2, 1 (c) 2, 1, 8 (d) 2, 8, 1 Open Answer ยป
Put tick (โ ) against correct choice and cross ( x ) against wrong choice in the following question: Number of valence electrons in Clโ ion are: (a) 16 (b) 8 (c) 17 (d) 18 Open Answer ยป
Put tick ( โ ) against correct choice and cross ( x ) against wrong choice in the following question: Isotopes of an element have (a) the same physical properties (b) different chemical properties (c) different number of neutrons (d) different atomic numbers Open Answer ยป
Put tick (โ ) against correct choice and cross ( x ) against wrong choice in the following question: Rutherfordโs alpha-particle scattering experiment was responsible for the discovery of (a) Atomic nucleus (b) Electron (c) Proton (d) Neutron Open Answer ยป
For the following statements, write T for โTrueโ and F for โFalseโ. (a) J.J. Thomson proposed that the nucleus of an atom contains only nucleons. (b) A neutron is formed by an electron and a proton combining together. Therefore, it is neutral. (c) The mass of an electron is about 1/2000 times that of proton. (d) An isotope of iodine is used for making tincture iodine, which is used as a medicine. Open Answer ยป
Composition of the nuclei of two atomic species X and Y are given as under X Y Protons = 6 6 Neutrons = 6 8 Give the mass numbers of X and Y. What is the relation between the two species? Open Answer ยป
The average atomic mass of a sample of an element X is 16.2 u. What are the percentages of isotopes ๐8 16 and ๐8 18 in the sample? Open Answer ยป
If bromine atom is available in the form of, say, two isotopes 35๐ต๐ 79 (49.7%) and ๐ต๐ 35 81 (50.3%), calculate the average atomic mass of bromine atom. Open Answer ยป