Atoms in the same period have the same number of energy levels, which also helps scientists predict how an atom will interact with other atoms. In Dimitri Mendeleev's periodic table, elements in the same vertical group have _____.
NonVisual Desktop Access (NVDA) is a free, open source, portable screen reader for Microsoft Windows. The project was started by Michael Curran in 2006. NVDA is programmed in Python. It currently works exclusively with accessibility APIs such as Microsoft Active Accessibility, IAccessible2 and the Java Access Bridge, rather than using specialized video drivers to intercept and interpret visual information. It is licensed under the GNU General Public License.
NvDA's features and popularity continued to grow. 2009 saw support for 64-bit versions of Windows as well as greater program stability in 2010. Major code restructuring to support third-party modules, coupled with basic support for Windows 8, became available in 2011.