The Answer is D
Because you add all of them to equal 9 atoms
Yes I would expect them too
A Framework for K–12 Science Education: Practices, Crosscutting Concepts, and Core Ideas (Framework) recommends science education in grades K–12 be built around three major dimensions: science and engineering practices, crosscutting concepts that unify the study of science and engineering through their common application across fields, and core ideas in the major disciplines of natural science.
Oh my lord lol I was do ready to help then I saw numbers