How do astronomers know the universe is expanding?
(please add the scientific principle you use)

Which statement correctly describes potassium iodide, ki? there is a one-to-one ratio of potassium ions to iodide ions. potassium gains electrons and iodine loses electrons during the reaction. the lattice is held together by potassium anions and iodide cations.

Can someone me with questions 12 and 13 plz.

What is the subscript for oxygen in its molecular formula