Choose the element from the list that best fits this description: "This element is in a family of elements that have characteristics of both metals and
nonmetals. It is often use as a semi-conductor in electric circuitry, but it is not
malleable."
Tellurium (Te)
Calcium (Ca)
Sodium (Na)
Argon (Ar)

Iknow #2 is d. i just need to know why

In vapor-liquid equilibrium in a binary mixture, both components are generally present in both phases. how many degrees of freedom are there for such a system? the reaction between nitrogen and hydrogen to form ammonia occurs in the gas phase. how many degrees of freedom are there for this system? steam and coal react at high temperatures to form hydrogen, carbon monoxide, carbon dioxide, and methane. the following reactions have been suggested as being involved in the chemical transformation:

What is happening when the water inside a kettle heats up and begins to boil