Cosmologists are scientists who study stars, galaxies, black holes, and other objects in the universe. In order to study the billions and billions of stars, cosmologists use highly advanced telescopes and create computer models to trace the stars’ motion.

What is one type of limitation that requires cosmologists to use these telescopes?

money
time
the size of the system
ethical concerns

The correct answer is 8 g.

Explanation:

During a physical change, the identity of the substance does not change, because no chemical reaction occurs. So, after the change, the amount of substance is still the same. Examples of physical changes are changes in the state of matter (solid-liquid-gas). If 8 grams of ice (water in the solid-state) are melted, after the melting process we will have 8 grams of water in the liquid-state, but still 8 grams of water.