Check your understanding on Lesson 1

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Across
  1. 4. This number represents the number of protons in an atom's nucleus.
  2. 5. The term for different atoms of the same element with different number of neutrons.
  3. 6. The maximum number of electrons in the innermost electron shell.
  4. 7. The negatively charged particle that orbits the nucleus.
  5. 8. This number represents the sum of protons and neutrons in an atom.
  6. 10. A vertical column in the periodic table where the atoms of the elements have the same number of valence electrons. .
Down
  1. 1. Particle in the nucleus with a positive charge.
  2. 2. A horizontal row in the periodic table where the atoms of the elements have the same number of electron shells.
  3. 3. The centre of an atom containing protons and neutrons.
  4. 4. The simplest unit of an element.
  5. 9. Particle in the nucleus with no charge.