Understanding Atoms, Elements, Molecules, and Compounds

What is the primary difference between a compound and a molecule?

• Molecules can only be broken down by physical means, while compounds cannot.

• Compounds can only be broken down by physical means, while molecules cannot.

• Molecules are made of atoms from the same element, while compounds are not.

• Compounds are made of atoms from the same element, while molecules are not.

What happens if you cut a single atom in half?

• It becomes two smaller atoms of the same element.

• It becomes a molecule.

• It retains its chemical identity.

• It changes its identity and becomes different elements.

Which of the following is true about elements?

• Elements are always molecules.

• Elements can only be single atoms.

• Elements can consist of multiple atoms bonded together if they are the same type.

• All elements are compounds.

How can compounds be broken down into simpler substances?

• By physical means

• By nuclear reactions

• By chemical means

• By heating

Which of the following is both an element and a molecule?

• Sodium chloride (NaCl)

• Carbon dioxide (CO2)

• Oxygen (O2)

• Water (H2O)