CLASS 7 · LEARNING KNOWLEDGE
Elements and compounds – basic principles
How it works
Elements are pure substances that consist of only one type of atom. Compounds consist of at least two different elements that are chemically bonded to one another. Elements and compounds differ in their properties. Each element has a chemical symbol. Compounds can be broken down into their elements by chemical reactions, elements cannot. The smallest unit of an element is the atom, that of a compound is the molecule or the formula unit.
Note
Elements consist of one type of atom, compounds of at least two different elements; compounds can be chemically broken down into elements, elements cannot.
Elements consist of one type of atom, compounds of at least two different elements; compounds can be chemically broken down into elements, elements cannot.
An example
Which substance is an element?
Oxygen is an element because it consists only of oxygen atoms. Water (H2O) is a compound because it consists of hydrogen and oxygen atoms.
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50 Exercises
To the learning unit →Own explanation and own practice exercises by AmyMath. Subject reference framework: Chemistry. The topic assignment may vary by federal state.