SyntaxKind Enum

var tree = XmlSyntaxTree.ParseText("<root><item /><item>text</item></root>");

var elementCount = 0;
foreach (var node in tree.GetRoot().DescendantNodes())
{
    if (node.Kind() == SyntaxKind.XmlElement)
    {
        // handle element
        elementCount++;
    }
}

// <item /> is an XmlEmptyElement, so only <root> and the second <item> are counted
Assert.Equal(2, elementCount);