Observed in Illinois on the first Monday of March every year, the holiday ostensibly honors Polish-born Revolutionary War cavalry officer Casimir Pulaski, though for most school kids with a four-day week, itâs probably just another sweet, sweet sleep-in day.
Yes, in chemistry a pure substance means either an element or a compound. Thus, hydrogen, oxygen, sodium, iron, copper etc. are pure substances; and so are compounds such as water, sugar, ammonia, sodium chloride, methane, ethanol etc. A compound is composed of two or more elements combined in a fixed ratio by mass. Like an element, a compound also has a distinct chemical identity. A mixture is not a pure substance as it is a collection of two or more elements/compounds in varying ratio. Air, sea water, gasoline, vegetable oils, steel etc. are mixtures.
Confidence votes 36. A pure substance is matter that contains only one type of particle. Compounds consist of two or more elements, but they are still pure substances because there is only one particle-the elements are chemically joined. (For example, water is a compound made of 2 parts hydrogen to 1 part oxygen.).ure substances contain only one type of particles. Even though each molecule in a compound is made of different atoms and each atom is made of protons, neutrons and electrons â¦ , a single moleculs is a single particle and since compounds contain only one type of particle (its molecules), it is a pure substance.