No substance always has the same composition and properties, unless that substance is only considered in one of the various phases of matter. An element would be the logical choice, but many compounds and even solutions are the same no matter what (of course dependent on phase).
heterogeneous mixture, DOES NOT APPEAR TO BE THE SAME THROUGHOUT
A Pure Substance
No. A pure substances has a definite and constant composition.
physical molecules with membranes
A SUBSTANCE is a material that has constant composition, regardless of its source, also said to be pure. This is opposed to an impure sample one with variable composition which would be called a MIXTURE. subutance
A Substance is a material that has constant composition, regardless of its source, also said to be pure.A substance is somethingRead more: What_is_a_substance_in_science
Pure substances fall into two categories: elements or compounds, both of which have constant compositions. H2O is a compound, and therefore a pure substance because its composition does not vary.
What is a substance with constant composition
Substance
A substance has constant and definitive composition Mixture is combinations of pure substances that have no constant and definitive composition: homogeneous mixture, heterogeneous mixture
A pure substance is classified by having a definite and constant composition. The substance can be either an element or a compound, but what makes the substance pure, is that it does not vary.
No. A pure substances has a definite and constant composition.
physical molecules with membranes
A SUBSTANCE is a material that has constant composition, regardless of its source, also said to be pure. This is opposed to an impure sample one with variable composition which would be called a MIXTURE. subutance
A pure substance:cannot be separated into 2 or more substances by physical or mechanical meansis homogeneous, ie, has uniform composition throughout the whole sampleits properties are constant throughout the whole sampleits properties do not depend on how it is prepared or purifiedhas constant chemical composition
A pure substance is a substance that consists solely of the same atoms/molecules.So a volume of water that contains only H2O is a pure substance. A block of iron that contains only Fe atoms is pure substance. A pure substance can be composed of atoms or molecules as I said before BUT they have to be exactly the same.A substance that has constant chemical composition and characteristics
A Substance is a material that has constant composition, regardless of its source, also said to be pure.A substance is somethingRead more: What_is_a_substance_in_science
No, helium is a pure substance and an element to be more specific. It has a constant composition making it a pure substance and it is homoatomic (has only one type of atom) which makes it an element.
A substance has a specific chemical composition while mixtures contain more than one substance.