What is the relationship between the classification of a reaction as endothermic or exothermic and the enthalpy of the reaction?

Electrons are extremely important to what area of technology? a) anti-aging research b) household product development c) electronics d) drug discovery

Great amounts of electromagnetic energy from our sun and other bodies in space travel through space. which is a logical conclusion about these electromagnetic waves? their energy must be very their frequency must be very low these waves can travel without a medium they only travel through a vacuum of space

How many moles are in 123.0 grams of kclo4?