Across
- 3. an electron that is found in the outermost shell of an atom and determines the atom's chemical properties
- 5. the mass of an atom expressed in atomic mass units
- 6. discovered positively and negatively charged particles in atoms and named the negatively charged particles electrons
- 9. one of the elements of group 17 of the periodic table, they combine with most metals to form salt
- 10. has 6 electrons in the outermost level and very reactive also includes sulfur in the group
- 11. describes something that occurs or repeats at regular intervals
Down
- 1. when objects that have the same charge reprel each other, while objects with opposite charges attract each other
- 2. the number of protons in the nucleus of an atom
- 4. one of the elements of group 13 having 3 electrons in the outer level of each element of this group
- 7. discovered there were no path's between levels of electrons, so electrons can jump from a path at one level to antother
- 8. a vertical column of elements in the periodic table; elements in this column share chemical properties