Ext → Unit Pretest
6
Select the correct answer from each drop-down menu.
An element has an atomic mass number of 16 and an atomic number of 7.
The element has __ protons and __neutrons

80 points pls brainliest 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?

Which atmospheric later is where earths northern and southern lights occur

Animals have a variety of adaptations,including trachea and gills, which allow this key process to occur. which provides the molecules necessary for cellular respiration and efficient atp synthesis?