Across
- 3. the smallest particle of an element that retains the chemical identity of the element; made up of positively charged protons, negatively charged electrons, and neutrons
- 9. the electrode at which oxidation occurs; it is the positively charged electrode within a cathode ray tube
- 13. the weighted average of the masses of the existing isotopes of an element; the sum of the masses of an element’s isotopes each multiplied by its natural abundance
- 15. elements that typically have a low melting point,a dull surface, breaks easily, and is a poor conductor of heat and electricity
- 16. an atom that has the same number of protons as another, identical atom, but with differing numbers of neutrons
- 17. an arrangement of the elements by their atomic numbers so that elements are periodic functions of their atomic numbers
- 19. gases elements in Group 8A (18); they do not readily react with other elements due to a satisfied octet; they are inert
- 20. the number of protons in the nucleus of an atom
- 24. the attractive force among the particles in the nucleus of an atom; in a stable atom, it overcomes the forces of repulsion among protons
- 25. elements in Group 2A of the periodic table; the ions of the elements in this group have 2+ charge
- 27. electrons in the outermost energy level of an atom
- 28. a stream of electrons produced at the negative electrode (cathode) of a tube containing a gas at low pressure
Down
- 1. a positively charged particle within the nucleus of an atom; it has a mass of 1.00720 amu
- 2. an electron that has absorbed energy and, therefore, exists at a higher energy level
- 4. the percentage of an isotope that occurs in nature
- 5. elements in Group 7A (17); they are the most reactive nonmetals
- 6. a horizontal row on the periodic table; the elements within the same period have the same number of energy levels
- 7. an element that typically has a high melting point, is ductile, malleable, and shiny, and a good conductor of heat and electricity
- 8. elements found on the stair-step line of the periodic table with properties of metals and nonmetals
- 10. elements that exist as diatomic molecules in nature; they include oxygen, hydrogen, nitrogen, fluorine, chlorine, iodine, and bromine
- 11. the normal state of an electron or atom; at this state the electron or atom has the lowest possible energy
- 12. elements found in the middle column of the periodic table; they have multiple oxidation states
- 14. the electrode at which reduction occurs; it is the negatively charged electrode within a cathode ray tube
- 18. elements in Group 1A of the periodic table; the ions of the elements in this group have a 1+ charge
- 21. number the sum of the number of protons and neutrons in the nucleus of an atom
- 22. a neutral particle within the nucleus of an atom; it has a mass of 1.00867 amu
- 23. a vertical column on the periodic table with similar electron configurations, chemical properties, and the same number of valence electrons
- 26. a negatively charged particle within an atom; it has a mass of 0.000549 amu