Matter

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Across
  1. 1. a substance that cannot be broken down into simpler substances by physical or chemical means.
  2. 3. a tiny particle that has mass and a positive electric charge
  3. 5. a tiny particle with approximately the same mass as a proton, but it has no electrical charge.
  4. 7. anything that has volume and mass
  5. 8. number The sum of the protons and the neutrons in an atom’s nucleus
  6. 10. Atoms of the same element that have different mass numbers
  7. 11. An atom that gains or loses one or more electrons from its outermost energy level has a net electric charge
Down
  1. 2. has little mass, but it has a negative electric charge
  2. 4. is made up of protons and neutrons
  3. 6. the smallest particle of an element that retains all the properties of that element
  4. 9. number The number of protons in an atom’s nucleus is