21. What type of cells are found on the retina and provide signals to the brain about incoming light? A photoreceivers
B optic cells
C photoreceptors
D retina cells​

Esign techniques and materials that reduce the negative environmental impact of a structure are referred to as

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.

The alkali metals (group 1) consist of lithium (3), sodium (11), potassium (19), rubidium (37), cesium (55), and francium (87). they are soft, metallic solids with low densities and low melting points. based on the data shown in figure 1, how many valence electrons do alkali metals share?