Across
- 3. number The number of protons in the nucleus of an atom.
- 4. particle The nucleus of the helium
- 8. The dense central part of an atom made up of protons and neutrons. It contains virtually all the atom’s mass but only a small portion of its volume.
- 11. A particle with a –1 charge and a mass of 9.11 × 10–31 kg found orbiting the nucleus in an atom.
- 12. the standard model of matter.
- 13. A packet of electromagnetic energy modeled as a particle that transmits electromagnetic force
- 15. uncertainty principal The principle that it is impossible to know both the energy or momentum (velocity) and the exact position of an electron at the same time.
- 16. A 3-dimensionsal region of space around a nucleus in which as many as 2 elections are likely to be found.
- 18. A neutral particle in an atom’s nucleus. It has a mass of 1.675 × 10–27 kg, slightly greater than the mass of a proton.
Down
- 1. A neutral particle with a centrally located nucleus, consisting of protons and neutrons, with elec- trons around it; the smallest particle that makes up an element and that is capable of chemical interactions.
- 2. rays The stream of electrons emitted from the cathode in a cathode-ray tube.
- 5. spectrum A spectrum showing only certain colors or wavelengths of light.
- 6. Having to do with quantities in which there are only separate, discrete values allowed.
- 7. Broglies hypothesis The concept that if waves can behave like particles, then particles can also be- have like waves.
- 9. of definite composition A law stating that every compound is formed of elements combined in mass ratios that are unique for that compound.
- 10. energy level A region around the nucleus containing a specified group of electrons in sublevels and orbitals.
- 13. A particle in an atom’s nucleus with a +1 charge and a mass of 1.673 × 10–27 kg.
- 14. spectrum A complete visual spectrum with no frequency gaps, emitted only by an ideal luminous object.
- 17. state An atom’s lowest energy state.