Excerpt is the short form of the whole article. If you want to get the whole article inside the loop you need to echo the tag get_the_content(), but to get short form or the article you can do two method.
FIRST AND EASY METHOD
you can simply echo get_the_excerpt();
SECOND METHOD BUT FLEXIBLE METHOD
you can abridge as much words as you like in this method. The syntax is as follow
$article_data = strip_tags(substr(get_the_content(), 0, 500));
echo $article_data.’ ….’;