The mass of an atom of another element is the ratio of its mass to the mass of a carbon atom. The mass number for neon is 20 but the atomic mass is 20.1797. The mass of the atoms increases. from left to right across the table.
Illinois growing zones range from zones 5-7. By looking at the map above and locating the approximate area in which you live, you will be able to find your Illinois hardiness planting zone. Simply compare the color-coded zones for your area with those of the legend on the right of the map.
Forget maps......Chicago is in zone 5...and gardeners wishing to plant those plants that are hardy to the Chicago area had better realize that zone 5 plants are the ones to buy. Besides zones are a relative term. Chicago is on the shores of Lake Michigan and the closer to the Lake, the more moderate the temperatures.