How many moles of helium are in 2.4 x 1024 helium atoms

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

The wave shown on the electromagnetic spectrum disturb the medium it passes through a)different frequency. b)the same frequency .

Explain how the integumentary system plays a crucial role in the ability to maintain homeoestasis