Select all of the answers that apply. dark matter may be
superhot gas between stars
cold matter that emits little radiation
the cause of the expansion of the universe
a new form of subatomic particle
the material from which living things develop

Which describes radioactive decay of a substance

New york city has 2,181 inhabitants per square mile. the state of alaska has 1.03 inhabitants per square mile. ecologists would say alaska has a low exponential growth population density birth rate carrying capacity

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?