One consequence of the third law of thermodynamics is that a. heat engines have efficiencies less than 100 percent. b. in some energy conversions, energy is not conserved. c. the work a heat engine produces is less than the waste heat it produces. d. engines cannot discharge waste heat.

What is driving behind plate tectonics (plate movment)? a) gravity only b) inertia c) convection and gravity d) the sun theres no option for science so i picked chemistry. plz

What is a difference between a mixture of elements and a mixture of compounds

Covalent bonds generally form when the bonded elements have a difference in electronegativity less than 1.5. subtract the electronegativities for the following pairs of elements and predict whether they form a covalent bond. electronegativity difference of c and c: ionic covalent electronegativity difference of mg and cl: ionic covalent