B. We are in the cenzoic era so what previously had happen to cause the life we live today was a huge mass extinction.... hope this helps!!

chlorine's atomic number and mass :
35,453 u

☝️follow the rules of brainly!
1. Observation-- making observations and taking notes about what you see, smell, hear, think, etc.
2. Question-- developing a question to test your observations.
3. Hypothesis-- creating an educated guess as to the answer of your question.
Answer 1) Option D : Discrete
Explanation : As in the example the scientist studies about the effects of growing human populations on the biodiversity which is found in a region, and where each region was selected had a different population density of humans from 1 to 10 million per 10 square miles. Then in each region the number of different species that can be found was recorded. So here the numerical data was collected for different regions. So, we can conclude it as discrete because when the variable takes on a countable number of values it is called as discrete.
Answer 2) Option D : The entertainment industry
Explanation : When people had enough time and money with them there was no need of creating the communications industry as it was a need not a luxurious thing. With the creation of Internet industry it is somewhat irrelevant. They had enough of time and money so building a labor industry seems to be a lame choice. So, the option of entertainment industry suits the best.
Answer: The atomic number is the number of protons in an atom of an element. In our example, krypton's atomic number is 36. This tells us that an atom of krypton has 36 protons in its nucleus.
Explanation: