Which of the following describes a circular current in a fluid that
occurs when the fluid is heated unevenly?
a
radiation cell
b conduction current
c
convection cell
d emission current

C- convection (convectional current)

Explanation:

Convection occurs in fluids e.g gases and liquids. It is the prices by which heat energy is transferred in a fluid by the actually movement of the heated fluid.

It is also called convectional current when the term current is used in the question.

in 1783 cavendish was working with his hydrogen gas and found that when he burned it and condensed the vapor it was water. this was very significant since it disproved the greek theory of elements completely since water was not a simple substance but the product of two gases. it was lavoisier who hearing of the experiment gave cavendish's gas the name hydrogen ("water-producer") and added that hydrogen burned by combining with oxygen and that water was a hydrogen-oxygen combination.

explanation:

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.