chemistry crossword

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Across
  1. 2. ,write calcium's symbol with it's atomic no.
  2. 3. ,the number of a chemical element in the periodic system, whereby the elements are arranged in order of increasing number of protons in the nucleus
  3. 5. , the sum of the numbers of protons and neutrons present in the nucleus of an atom.
Down
  1. 1. , element with a symbol 'H' and atomic no. 1
  2. 2. , abbreviations used in chemistry for chemical element, functional groups and chemical compounds.
  3. 4. , element with a symbol 'NE' and atomic no. 10