Analysing and identifying substances

• Pure substances are substances that consist of only one element or only one compound.
• Formulations are mixtures designed with a specific purpose.
• Chromatography can be used to separate a mixture of solutes.
• Lab tests can be used to identify common gases.
• Pure substances are used in chemistry in a different way from their everyday meaning.
• A pure substance consists of only one element or only one compound.
• A substance that consists of only one element or only one compound is used in chemistry in a different way from its everyday meaning.
• Pure substances are not the same as substances that are not chemically changed.
• A pure substance is a substance that consists of only one element or only one compound.
• A substance made of one type of atom only or one compound is a pure substance.
• A substance formed by the chemical union of two or more elements is a pure substance.
• Two or more substances that are not joined together consist of two or more different substances, not chemically joined together.
• The components of a mixture can usually be separated without chemical reactions.
• Different types of chemical substance an element contains just one type of atom.
• The smallest part of an element that can exist is an atom.
• A compound contains two or more types of atom joined together.
• A mixture contains two or more different substances that are not joined together.
• The different substances in a mixture can be elements or compounds.
• Pure substances have a sharp melting point.
• The melting point of a pure substance is close to its boiling point.
• Mixtures melt over a range of temperatures.
• The temperature at which a solid changes into a liquid when it is heated is known as the melting point.
• The process that occurs when a solid turns into a liquid when it is heated is known as melting.
• When a pure substance changes state, the temperature stays the same.
• An impure substance consists of more than one element or compound.
• The temperature changes slightly as an impure substance changes state.