Across
- 1. positively charged particles
- 4. most reactive non metals
- 8. mass of one atom of an element
- 10. invisible negatively charged particle that orbits the nucleus of an atom
- 12. from the total number of protons,
- 13. positively charged centre of an atom; contains protons and neutrons
- 16. which are formed from two nonmetals
- 17. least reactive substances
- 18. when energy is absorbed into, especially during a chemical reaction
- 20. group 1 metals in the periodic table, not including hydrogen;the most reactive of the metals
- 21. that are made up for 2 or more substances
- 24. the orbit of an electron around the nucleus of an atom
- 25. and electrons of that atom; measured in
- 27. shiny, malleable, ductile element that conducts electricity
- 28. anything that has mass and occupies space
Down
- 2. The non-metal in the periodic table with the symbol O
- 3. also known as rusting, is caused when oxygen reacts with a metal
- 5. measure of atomic mass; 1 amu is equal to 1/12th the mass of a carbon-12 atom
- 6. second most reactive elements, group 2 of the periodic table
- 7. when energy is given off from, especially from a chemical reaction
- 9. substances that are made up of one type of matter and have a unique set of characteristics
- 11. chemical reaction that occurs when oxygen reacts with a substance to form a new substance and give off energy
- 14. atom that has become electrically charged because it has lost or gained electrons; a positive ___ is an atom that has lost one or more electrons; a negative ___ is an atom that has gained one or more electrons
- 15. which are formed from a nonmetal and a metal which balance out
- 19. number of protons in the nucleus of one atom in an element
- 22. dull, brittle insulators
- 23. has the properties of metals and non metals
- 26. neutral particles