Is it possible to set a modifier to a block in BEM?

Question

css

Actually, the question is in the SUBJECT.
I mean, is it acceptable to write like this:

<div class="block--mod">
  <div class="block--mod__elem"></div>
  <div class="block--mod__elem--mod"></div>
</div>

Answer 1

<div class="block block--mod">
  <div class="block__elem block__elem--mod"></div>
  <div class="block__elem block__elem--mod"></div>
</div>

Answer 2

Class modifier one is not used. That is, you always need to write at least
2
classes
.
If the block is of the same style, then for the elements such a modifier. If the block is different then other modifiers for elements
For example
block block_big
block__elem block__elem_big
block block_small
block__elem block__elem_small