7th Activity

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Across
  1. 3. The imaginary circular paths around the nucleus where electrons are located.
  2. 6. The valency of nitrogen in ammonia (NH3) gas.
  3. 8. A substance formed by the chemical combination of two or more elements in a fixed ratio.
  4. 9. The neutral sub-atomic particle present in the nucleus.
  5. 10. The total number of protons & neutrons in the nucleus of an atom is called ________ number.
Down
  1. 1. The vertical columns of the periodic table.
  2. 2. Two chlorine atoms combine to form one molecule of chlorine (Cl₂). Therefore, the ________ of chlorine is two.
  3. 4. The only polyatomic basic radical.
  4. 5. The total number of atoms present in one molecule of Calcium oxide.
  5. 7. An acid radical that is made up of oxygen and hydrogen atoms only.