Across
- 2. Negatively charged particle orbiting the nucleus.
- 5. Positively charged particle in the nucleus.
- 8. Configuration that makes atoms stable and unreactive.
- 9. Negatively charged ions formed by non-metals.
- 10. Dense core containing protons and neutrons.
- 12. Elements with properties of both metals and non-metals.
- 14. Tendency of an element to undergo chemical reactions by readily loosing or gaining electrons.
- 15. Number of protons in an atom's nucleus.
- 16. Electrons in the outermost shell of an atom, influencing reactivity.
- 18. Elements that are poor conductors and brittle.
- 19. Group 18 elements, stable and non-reactive due to full valence shell, 8 valence electrons. Non-metals.
- 20. Group 17 elements, very reactive non-metals, seven valence electrons.
- 21. Columns in the periodic table with similar properties.
- 22. Elements that are good conductors and malleable.
- 23. Number Total number of protons and neutrons.
Down
- 1. Reactivity increases down a group and decreases across a period.
- 2. Layers around the nucleus where electrons reside.
- 3. Neutral particle located in the nucleus.
- 4. Group 1 elements, highly reactive with water, one valence electron.
- 6. Group 2 elements, reactive but less than alkali, two valence electron.
- 7. Distribution of electrons among shells e.g. 2, 8, 8.
- 11. Circles or energy levels, where electrons are arranged around nucleus.
- 13. Rows in the periodic table indicating energy levels.
- 17. Positively charged ions formed by metals.