Alkanes are linear, or branching, compounds that are made of varying numbers of carbon atoms that are all saturated with hydrogen atoms. The formula for an alkane is CnH(2n+2). This means that the number of hydrogen atoms equals twice the number of carbon atoms, plus two. Methane is the simplest hydrocarbon possible.
Glucose is virtually the sole fuel for the human brain, except during prolonged starvation. The brain lacks fuel stores, thus requires a continuous supply of glucose. It consumes about 120 g daily which corresponds to an energy input of 420 kcal (1760 KJ), accounting for some 60% of the utilization of glucose by the whole body in the resting state.
You can't really expect to find water stored as a gas, as it cools to a liquid at room temperature. You could easily find evaporated water on a stovetop by boiling water, though.
Democritus is a Greek theorist that believes that atom is the smallest part of the substance. Atom, as he defined, is an indivisible entity. Leuccipus was Democritus' teacher who also believed on that notion. All matter are made up of atoms. If atoms are intact, the property of the substance is firm and solid while if the atoms are much apart, it would be described as a gas. Aristotle had a different belief of matter. He believed that the composing entities of matter are the four elements. However, this notion was rejected and proven through scientific inquiries about atoms and subatomic particles