Across
- 5. The smallest part of a chemical element that can exist
- 7. An element or substance that is not metal
- 9. A substance or matter in a state which it will expand freely to fill the whole space without having a fixed shape and volume.
- 10. The time taken for radioactivity of a specified isotope to fall to half its original value
- 13. A particle smaller than an atom such as neutrons or a cluster of particles like alpha particles
- 15. A subatomic particle with a negative electric charge which is found in all atoms and accounts as the primary carrier of electricity in solids.
- 16. occurs in an atomic nuclei with a positive electric charge,
- 17. The theory that all matter is made up of atoms
- 19. The emission of ionizing radiation or particles caused by the spontaneous disintegration of atomic nuclei
Down
- 1. A reactive non-metallic element that forms strong acidic compounds with hydrogen from simple salts that can be made
- 2. An element whose properties are between those of metals and solid non-metals or semiconductors.
- 3. two or more forms of the same element that contain an equal amount of protons but different amounts of electrons within their nuclei,
- 4. Any of the gaseous elements helium, neon, krypton, xenon and radon occupying group 0 of the periodic table
- 6. A subatomic particle of the same mass as a proton, but has no electric charge, occurs in all atomic nuclei except ordinary hydrogen.
- 8. Any substance that has mass which occupies a space by having volume
- 11. The total number of protons and neutrons within a nucleus
- 12. A solid material which is typically hard, shiny, malleable, fusible and has good electrical and thermal conductivity.
- 14. The determination of the age or date of an organic matter from the relative proportions of carbon isotopes carbon-12 carbon-14 that it contains.
- 18. The number of protons in the nucleus of an atom, which is characteristic of a chemical element and determines its place in the periodic table