Union element alignment

If I have a union, C standard guarantees that the union itself will be aligned to the size of the largest element.

union U {
    long l;
    int i;
    short s;
    char c[2];
} u;

But what does it say about alignment of individual union elements inside the union? Is the following expression guaranteed to be true?

(&u.l == &u.i) && (&u.i == &u.s) && (&u.s == &u.c[0])