Hydrogen, oxygen and nitrogen are counted as some most important elements and found abundantly. About 75% of this universe is composed of hydrogen and helps different other matters to sustain. Large starts and planets, electrons and protons are also composed of hydrogen.
A sheet tab appears at the bottom of your worksheet. It has the name of the worksheet on it, which can be changed and you can also change its colour. This can be done by right clicking on it and picking the option from the shortcut menu that appears. By clicking a sheet tab, you can make that sheet the active sheet so that you can work on it.
In Excel 2010, you can repeat item and field labels in a PivotTable report to make a PivotTable easier to read. You can repeat labels for nested items per field in rows or columns. You can also turn the option to repeat labels on or off for all fields in the PivotTable at the same time.