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Significant Figures and Matter

Significant Figures and Matter

Author: Christene Lohse
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Physical Matter Properties - Chemical Matter Properties

Physical matter properties include color, odor, density, melting point, boiling point and hardness. Physical properties are divided into intensive and extensive properties. Intensive properties are used to identify a substance and do not depend upon the amount of substance (density). Extensive properties depend on the quantity of the substance (mass, volume). Chemical matter properties include flammability and reactivity.

Three States of Matter

States of matter are the different phases which matters can take - gas, liquid and solid. Gas has no fixed shape and conforms to the volume of its container. A liquid has a distinct volume but assumes the shape of its container. A solid has definite shape and volume, regardless of its container. In the case of H20 steam is a gas, water is a liquid and ice is a solid. Most substances are more dense in their solid form, but water is an exception.

Changes in Matter

Changes in matter can be classified as either physical or chemical, like matter properties. Physical changes include changes in physical appearance but not composition. All changes in state of matter are physical changes. Chemical changes involve changes in chemical composition and require chemical reactions.

Conservation of Mass

The law of conservation of mass states that mass is neither created nor destroyed. In a closed system, mass of reactants is equal to mass of products. The law of conservation of mass is related to the law of conservation of matter.

Law of Definite Proportions - Law of Multiple Proportions

The law of definite proportions, also known law of definite composition, states that regardless of the amount, a pure compound always contains the same elements in the same proportions by mass. Law of multiple proportions, also known as Dalton's Law, states that when one element combines with another to form more than one compound, the mass ratios of the elements in the compounds are simple whole numbers of each other.


Mixtures are composed of pure substances and elements, but unlike compounds these substances retain their own chemical identities and properties. Mixtures can be homogeneous or heterogeneous. Homogeneous mixtures are the same throughout and are called solutions. Heterogeneous mixtures don't have uniform composition.

Elements and Compounds

Elements and compounds are differentiated by their composition. Elements cannot be decomposed into simpler substances. Compounds are composed of two or more elements, but the chemical identities and properties of these elements change when they form a compound. Mixtures on the other hand are composed of elements which retain their chemical identities.