Substance example sentences

The water that washes off roads and rooftops carries harmful substances with it.We all appreciate the strong dependence of industry and agriculture upon mineral deposits and the substances manufactured from them.The enthalpy of solution at infinite dilution is the enthalpy change observed on dissolving the substance in an infinite amount of solvent when the interactions between the ions (or solute molecules) are negligible.The undigested, unabsorbed substances called faeces enters into the caecum of the large intestine through ileo-caecal valve, which prevents the back flow of the faecal matter.Actually, chemical reactions involve the breaking and making of bonds between atoms to produce new substances.This process of conversion of complex food substances to simple absorbable forms is called digestion and is carried out by our digestive system by mechanical and biochemical methods.Hazardous wastes such as inflammables, composite explosives or highly reactive substances are produced by industries dealing in metals, chemicals, drugs, pharmaceuticals, dyes, pesticides, rubber goods etc.A luminous flame is seen when the atoms of the gaseous substance are heated and start to glow.A naturally occurring substance that has a definite chemical composition is a mineral.Certain marine brown and red algae produce large amounts of hydrocolloids (water holding substances), e.g., algin (brown algae) and carrageen (red algae) are used commercially.The standard enthalpy of reaction is the enthalpy change for a reaction when all the participating substances are in their standard states.In a decomposition reaction, a single substance decomposes to give two or more substances.The enthalpy change that accompanies melting of one mole of a solid substance in standard state is called standard enthalpy of fusion or molar enthalpy of fusion, ?fusH0.The presence of polluting substances in water and soil are hazardous for physical health.For example, if we are studying the reaction between two substances A and B kept in a beaker, the beaker containing the reaction mixture is the system and the room where the beaker is kept is the surroundings.