What coefficient is missing in C2H4 + (?)O2 → 2CO2 + 2H2O?

Adiver in midair has an angular velocity of 6.0 rad/s and a moment of inertia of 1.2 kg·m2. he then pulls is arms and legs into a tuck position and his angular velocity increases to 12 rad/s. the net external torque acting on the diver is zero. what is his moment of inertia in the tuck position?

Which type of bond is found between the atoms of a molecule? a. metallic b. delocalized electron c. covalent d. ionic

Wavelength,frequency,and energy are related.what happens to a wave as it’s wavelength gets shorter?