Which highly reactive gas was probably absent from the earth's primitive atmosphere?

What can be the use of smoke transformed into liquid?

The concept of empiricism states that all rationally accepted knowledge is determined from experience. francis bacon was one of the first scientists to promote this theory. what was it’s impact on society?

Which statement about hf is true? it is zero for any compound in its standard state. it is positive when the bonds of the product store more energy than those of the reactants. it is negative when a compound forms from elements in their standard states. it is zero for any element that is in the liquid state.