Atoms, Molecules, & Compounds

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What is an atom?

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An atom is the smallest unit of matter that retains the properties of an element. It consists of a nucleus containing protons and neutrons, surrounded by electrons.

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What is a molecule?

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A molecule is a group of two or more atoms bonded together. Molecules can be made up of the same type of atoms (like O2) or different types (like H2O).

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What is a compound?

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A compound is a substance formed when two or more different elements are chemically bonded together, such as water (H2O) or ammonia (NH3).

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What is a monoatomic element?

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A monoatomic element consists of single atoms that are not bonded to each other, such as helium (He) or oxygen (O).

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What is a diatomic molecule?

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A diatomic molecule is a molecule composed of two atoms, which can be of the same or different elements, such as O2 (oxygen) or CO (carbon monoxide).

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What is the chemical formula for water?

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The chemical formula for water is H2O, indicating it is made of two hydrogen atoms and one oxygen atom.

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What is the chemical formula for ammonia?

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The chemical formula for ammonia is NH3, indicating it is made of one nitrogen atom and three hydrogen atoms.

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What is the difference between an element and a compound?

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An element is a pure substance made of only one type of atom, while a compound is made of two or more different types of atoms chemically bonded together.

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What does the subscript in a chemical formula indicate?

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The subscript in a chemical formula indicates the number of atoms of the element present in the molecule. For example, in H2O, the '2' indicates there are two hydrogen atoms.

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What is an example of a monoatomic element?

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An example of a monoatomic element is helium (He), which exists as single atoms.