What type of reaction is H2SO4 + HI = H2S + I2 + H2O

In a water molecule, hydrogen and oxygen are held together by a(an) bond. a) double covalent b) ionic c) nonpolar covalent d) hydrogen e) polar covalent

Which of these is an example of pseudoscience? a) predicting the time of sunrise based on data on position of earth b) predicting the date of the moon phases based on data on position of earth c) predicting eclipses based on the position of the sun and the moon d) predicting future events in a person's life based on the position of the moon

Which of the following is true about the speed of light? it depends on the wavelength.