Identify two observations that a model of the universe would need to explain to be useful

"Theory relates to a model in science because it presents the possible paradigms and patterns of the said concept and fact. It explains and elaborates the phenomenon of why it happened, how it happened and the factors that are invovlved in the process. A theory is a possible explanation of certain occurence.

in addition, any time a scientific theory is challenged, it means it's not a good theory. And this statement is not valid. In theoretical models, they are revisited when there are further studies and discoveries found in a certain area where they can be remodeled and reintegrated instead of disregarding its credibility. Models, theories and paradigms are not challenged but rather encouraged, they are supported in many studies since these theories and models were created in order for us to understand a certain phenomenon but it would likely help the scientific society to be updated in the new forms or spheres of improvement rather than discouragement."

h let me think about that

the correct option is c.

isotopes refers to different forms of the same element with the same atomic number but different mass number as a result of difference in their neutron numbers. isotopes have different relative atomic mass but share the same chemical properties.