en_tn/ezk/12/15.md

know that I am Yahweh

When Yahweh says that people will know that he is Yahweh, he is implying that they will know that he is the one true God who has supreme authority and power. See how you translated this in Ezekiel 6:7. Alternate translation: "understand that I am Yahweh, the one true God" or "realize that I, Yahweh, have supreme power and authority" (See: rc://en/ta/man/jit/figs-explicit)

when I scatter them among the nations and disperse them throughout the lands

These two phrases mean basically the same thing. Alternate translation: "when I cause them to separate from each other and live in different nations" (See: rc://en/ta/man/jit/figs-parallelism)