PHYSICAL SCIENCE 1

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Across
  1. 5. A substance made of only one type of atom, like gold or oxygen.
  2. 6. Atoms of the same element with different numbers of neutrons.
  3. 7. A huge explosion of a star at the end of its life.
  4. 10. A negatively charged particle that orbits an atom's nucleus.
  5. 14. A light, non-reactive gas often used in balloons.
  6. 15. A group of atoms bonded together, like water (H₂O).
  7. 17. A common metal that is strong and magnetic.
  8. 18. The total mass of an atom, mostly from its protons and neutrons.
  9. 19. The simplest and most common element in the universe.
  10. 20. The smallest unit of matter that makes up everything.
Down
  1. 1. The process of making new elements inside stars.
  2. 2. The massive explosion that started the universe.
  3. 3. The distance between two peaks of a wave, like in light or sound.
  4. 4. An element that has properties of both metals and non-metals.
  5. 8. A particle of light or electromagnetic energy.
  6. 9. An ancient practice that combined science and magic, aimed at transforming substances.
  7. 11. A type of hydrogen with one extra neutron.
  8. 12. A state of matter like a gas but with charged particles.
  9. 13. When light from an object moving away from us looks redder.
  10. 16. A positively charged particle in an atom's nucleus.