The interval between the gridlines in an Excel chart is typically blank, but you can highlight the intervals using an alternating pattern by changing the formatting for the gridlines themselves.

To add a title to your chart, click the Chart Title button in the Labels group within the Layout tab, and then select where to position the chart title. For example, click the Above Chart button to ...

To add a title to your chart, click the Chart Title button in the Labels group within the Layout tab, and then select where to position the chart title. For example, click the Above Chart button to ...