Chemistry Crossword

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.

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.