118 Elements and Their Symbols and Atomic Numbers:The Periodic Table is a well-organized chart that contains all 118 known ...

Players read questions about energy levels and score points by picking the correct element as the answer ... energy level and six electrons on the second energy level. Since this atom has a total of ...

For example, lithium (Li), sodium (Na) and potassium ... group of elements below were grouped together because they tended to combine with two other atoms. For example, one oxygen atom combines ...