Hmm.... Oxygen support combustion. Other than that, rusting occur when oxygen is combined with metal. When iron rusts, it combines with oxygen. Hope it helps.
Answer:
H2O> NH3> CH4
Explanation:
According to valence shell electron pair repulsion theory (VSEPR), bond angles and repulsion of electron pairs depends on the nature of electron pairs on the central atom of the molecule. Lone pairs cause more repulsion (and distortion of bond angles) than bond pairs). Lone pair- lone pair repulsion is greater than lone pair bond pair repulsion.
Water contains two lone pairs on oxygen hence it experiences the greatest repulsion. Ammonia has only one lone pair on nitrogen hence there is lesser repulsion between lone pairs and bond pairs. Methane possess only bond pairs of electrons hence it has the least repulsion.
Sound actually travels slower in air.This is because sound is kinetic energy and has to pass from molecule to molecule.In gas the molecules are farther apart taking more time for it to pass,in water the molecules are closer so it takes less time for the sound to get from one molecule to another and with cast iron (since it's very dense) the molecules are very close allowing sound to travel quickly with ease.
The scientist should form a hypothesis and design an experiment.
This way they can properly follow the scientific process.
