Across
- 2. – Neutral particles in an atom’s nucleus.
- 7. – A reaction that absorbs heat.
- 10. – Number of protons in the nucleus of an atom.
- 11. – A bond formed by sharing electrons.
- 12. – Positively charged particles in an atom's nucleus.
- 13. – A reaction that releases heat.
Down
- 1. – A substance made of two or more substances not chemically combined.
- 3. – A short-hand way to represent a chemical reaction.
- 4. – The basic unit of a chemical element.
- 5. – Particles with a negative charge found outside the nucleus.
- 6. – A chart that organizes all known elements by atomic number.
- 8. – The center of an atom, containing protons and neutrons.
- 9. – A bond formed by the transfer of electrons.
- 11. – Two or more elements chemically combined.
- 13. – A pure substance made of only one kind of atom.