Across
- 4. a measure of the size of its atoms, usually the mean or typical distance from the center of the nucleus to the boundary of the surrounding shells of electrons
- 6. an outer shell electron that is associated with an atom, and that can participate in the formation of a chemical bond if the outer shell is not closed.
- 7. ion that consists of more than one atom
- 8. any of the soft, light, reactive metals of Group 1 of the periodic table: lithium, sodium, potassium, rubidium, cesium, and francium
- 10. metal - any of various chemical elements that have valence electrons—i.e., electrons that can participate in the formation of chemical bonds—in two shells instead of only one.
- 13. an atom or molecule that carries an electric charge
- 14. the number of protons minus the number of electrons
- 17. a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well
- 18. the mass of an atom of a chemical element expressed in atomic mass units. It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes.
- 19. a positively charged ion (i.e. one that would be attracted to the cathode in electrolysis)
- 20. the fixed amount of energy that a system described by quantum mechanics, such as a molecule, atom, electron, or nucleus, can have
- 23. the fixed amount of energy that a system described by quantum mechanics, such as a molecule, atom, electron, or nucleus, can have
- 24. the number of protons in the nucleus, which determines the identity of an element, its place in the periodic table, and its chemical properties
- 25. a stable subatomic particle with a charge of negative electricity, found in all atoms
- 27. any of the gaseous elements helium, neon, argon, krypton, xenon, and radon, occupying Group 0 (18) of the periodic table. They were long believed to be totally unreactive but compounds of xenon, krypton, and radon are now known
- 29. a subatomic particle of about the same mass as a proton but without an electric charge, present in all atomic nuclei except those of ordinary hydrogen
Down
- 1. a tendency of an atom to attract shared electrons
- 2. a negatively charged ion (i.e. one that would be attracted to the anode in electrolysis)
- 3. arrangement of electrons in orbitals around an atomic nucleus
- 5. series of chemical elements comprises the 15 metallic chemical elements with atomic numbers 57–71, from lanthanum through lutetium
- 9. a synthetic element is one of 24 chemical elements that do not occur naturally on Earth
- 11. an element (e.g. arsenic, antimony, or tin) whose properties are intermediate between those of metals and solid nonmetals or semiconductors
- 12. the minimum amount of energy required to remove the most loosely bound electron of an isolated neutral gaseous atom or molecule
- 15. any of six chemical elements in group 2 of the periodic table: beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr). While not as reactive as the alkali metals, this family knows how to make bonds very easily
- 16. any of the elements fluorine, chlorine, bromine, iodine, and astatine, occupying group VIIA (17) of the periodic table; reactive nonmetallic elements that form strongly acidic compounds with hydrogen from which simple salts can be made
- 21. a system consisting of a small, dense nucleus surrounded by orbiting electrons—similar to the structure of the Solar System, but with attraction provided by electrostatic forces in place of gravity.
- 22. a stable subatomic particle occurring in all atomic nuclei, with a positive electric charge equal in magnitude to that of an electron, but of opposite sign
- 26. each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties
- 28. a chemical element that mostly lacks the characteristics of a metal. Physically, a nonmetal tends to have a relatively low melting point, boiling point, and density