Atoms and the Periodic Table Crossword

QUESTIONS LIST: Nucleus : Part of the atom comprising protons and neutrons (7), Oxidation : Process that causes reactive metals to discolour in air (9), Mass : Protons and neutrons have a relative ________ of 1 (4), Boron : The only non-metal Group 3 element (5), Chemical Symbol : H is the ______________ of hydrogen (8,6), Argon : Gas used to stop Cs and Rb from oxidising in storage (5), Lithium : Metal harder than sodium and in the same group (7), Positive : Protons have a ______________ charge (8), Sodium : Na is the chemical symbol for ____________ (6), Fluorine : Non-metal with a mass number of 19 (8), Electrons : Negatively-charged sub-atomic particles (9)