Which statement about pure substances and molecules is correct?(1 point) Responses Molecules cannot be pure substances. Molecules cannot be pure substances. All pure substances are molecules. All pure substances are molecules. Pure substances cannot be molecules. Pure substances cannot be molecules. All molecules are pure substances.
All pure substances are molecules.
The correct statement is: All molecules are pure substances.
The correct statement is: All pure substances are molecules.
To understand why this statement is correct, let's break it down:
1. Pure substances: Pure substances are defined as substances that are made up of only one type of atom or molecule. They have a fixed composition and specific physical and chemical properties.
2. Molecules: Molecules are groups of two or more atoms that are bonded together. They can be made up of the same type of atoms (as in elemental molecules like O2) or different types of atoms (as in compounds like H2O).
Now, let's analyze the other statements:
1. Molecules cannot be pure substances: This statement is incorrect. Molecules can indeed be pure substances if they consist of only one type of atom, like elemental molecules such as O2 or N2.
2. All pure substances are molecules: This statement is correct. All pure substances are either made up of atoms (elemental substances) or molecules (compound substances). As a compound is a substance formed by the chemical combination of two or more different atoms, all compounds can be considered molecules.
3. Pure substances cannot be molecules: This statement is incorrect. Pure substances can be either elemental substances (made up of only one type of atom) or compound substances (made up of different types of atoms bonded together in a molecule).
4. All molecules are pure substances: This statement is incorrect. While pure substances can be molecules, not all molecules are pure substances. Molecules that are comprised of different types of atoms are considered compound substances rather than pure substances.
In conclusion, the correct statement is that all pure substances are molecules, as pure substances can be either elemental substances composed of one type of atom or compound substances composed of different atoms bonded together in a molecule.