19. Which statement best describes the reaction taking place in the core of a star during its main sequence stage? a. Decay of carbon-14 to carbon-12
b. Fusion of hydrogen into helium
c. Fission of helium into hydrogen
d. Fusion of hydrogen into water vapor

Which describes interactions between substances and stomata during photosynthesis? check all that apply. oxygen enters stomata. oxygen is released through stomata. carbon dioxide enters stomata. carbon dioxide is released through stomata. hydrogen enters stomata. hydrogen is released through stomata.

Three alkali metals in group 1 are a. calcium, strontium, barium b. boron, aluminum, gallium c. sodium, potassium, rubidium d. fluorine, iodine, chlorine

When balancing a chemical equation: