The table below shows the initial and final masses of a radioactive material in a container. Initial mass (in kilograms) 0.8
Final mass (in kilograms) 0.05
Based on the table, which of these conclusions is correct?
The half life of the material is three years.
The half life of the material is four years.
The mass of the material was 0. 1 kilograms after four half lives.
The mass of the material was 0.1 kilograms after three half lives.​

What is the difference between a scientific hypotheses and a scientific theory?

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?

What are levels of ecology and how can we remember them