NEED HELP NOW. A chemical reaction occurs that involves combining 1 atom of zinc with 2 atoms hydrogen and 2 atoms of chlorine. After the reaction, how many atoms of each element will there be? 1 zinc, 2 hydrogen, 2 chlorine2 zinc, 2 hydrogen, 2 chlorine2 zinc, 1 hydrogen, 2 chlorine3 zinc, 2 hydrogen, 2 chlorine

Adigestive system that is a series of tubes beginning at the mouth and ending at the anus is a digestive system.

Which of the following shows the correct order in which light information travels through the eye? (2 points) lens, pupil, retina, optic nerve pupil, lens, retina, optic nerve pupil, lens, optic nerve, retina lens, pupil, optic nerve, retina

20 point pls brianliest 1. what does a red shift mean? blue shift? 2. describe the big bang theory. according to this theory, how old is the universe? 3. scientists believe the universe is expanding. what is the evidence that supports this? 4. describe a nebula. 5. describe the 3 types of galaxies. what is a barred spiral galaxy? 6. what is a light year? how far is alpha centauri from earth? 7. describe the universal law of gravitation. be sure to include gravitational force between two objects. 8. describe the planets’ orbits around the sun. 9. what is the asteroid belt? where is it located? 10. describe rotation and revolution of earth. what determines an earth day and year? 11. how do galaxies exist? 12. compare and contrast the inner and outer planets. 13. what causes the seasons?