1 / 1                                                    ATOMS AND MOLECULES                                                         ASSIGNMENTQ1. Fill In The Blanks1. During a chemical reaction, the sum of the _________ of the reactants and products remain unchanged.2. In a pure chemical compound, elements are always present in a ________ proportion by mass.3. Clusters of atoms that act as an ion are called __________ ions.4. In ionic compounds, the charge on each ion is used to determine the ________of the compound.5. The Avogadro constant _________ is defined as the number of atoms in exactly ________ of crbon-126. Mass of 1 mole of a substance is called its __________.7. The abbreviation used for length names of elements are termed as their _______.8. A chemical formula is also known as a ________.9. Those ions which are formed from single atoms are called _________.10. Ionic compounds are formed by the combination between ________ an ______.11. The valency of an ion is _________ to the charge on the ion.12. Mole is a link between the __________ and __________.13. The SI unit of amount of a substance is __________.Q2. Calculate the formula mass of each of the following and round your answer to the nearest 0.1 u.          (a) NaHCO3          (b) K2Cr2O7          (c) (NH4)2CO3          (d) AI2 (SO4)3          (e) CuSO4.5H2O?Q3 (a) Give two symbols which have been derived from the "English names" of   the elements.     (b) Give two symbols which have been derived from the " Latin names" of the elements.Q4  i) Distinguish between an atom and a molecule.    (ii) Differentiate between atom and ion.Q5. Write formulas for ionic compounds formed from:          (a) Na and F          (b) Na and O,          (c) Mg and F          (d) AI and CQ6. 10.0 g CaCO3 on heating gave 4.4 g of CO2 and 5.6 g of CaO. Show that these observations are in agreement with law of conservation of mass.​