M1 Pretest

What is the smallest unit of matter that retains an element's chemical identity?

• Atom

• Molecule

• Ion

• Compound

Which of the following describes a substance composed of only one type of atom?

• Element

• Mixture

• Compound

• Molecule

Water (H_2​O) is an example of a:

• Molecule

• Element

• Atom

• Mixture

 Which particles are found in the nucleus of an atom?

• protons and neutrons

• neutrons and electrons

• only protons

• electrons and protons

How are compounds different from mixtures?

• Compounds have a variable composition, while mixtures have a fixed composition.

• Compounds involve chemical bonds between elements, while mixtures do not.

• Mixtures are always homogeneous, while compounds are always heterogeneous.

• Compounds can be separated by physical means, while mixtures cannot.

Which of the following is considered an element?

• Oxygen (O​)

• Carbon Dioxide (CO₂​)

• Salt (NaCl)

• Water (H₂​O)

The atomic number of an element is determined by the number of:

• protons

• neutrons

• electrons

• protons and neutrons

A molecule is formed when two or more atoms are held together by:

• gravitational force

• physical forces

• chemical bonds

• magnetic attraction

Which of the following is a compound?

• Gold (Au)

• Air

• Nitrogen (N)

• Methane (CH₄)

The chemical formula C₆​H₁₂​O₆​ represents a:

• Isotope

• Compound

• Mixture

• Element