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.
This is a much-needed update using the 30-year period of 1976-2005 versus the old USDA map which used the period 1974-1986. One of the outstanding features of the new map is the northward shift of the hardiness zones in Illinois. For example, the boundary between zones 5 and 6 have shifted about 60 miles to the north.