Chemistry Quiz: Elements and Atoms

Comparing Elements, Compounds, and Mixtures

• Elements are pure substances with one type of atom.
• Compounds are pure substances with two or more different types of atoms bonded together.
• Mixtures are combinations of two or more substances that are not chemically bonded.

Subatomic Particles

• Atoms are made up of three subatomic particles: protons, neutrons, and electrons.
• Protons have a positive charge and are located in the nucleus.
• Neutrons have no charge and are located in the nucleus.
• Electrons have a negative charge and orbit the nucleus.

Isotopes

• Isotopes are atoms of the same element with different numbers of neutrons.
• The number of protons is the same, but the number of neutrons varies.
• Isotopic symbols display the element symbol, mass number, and atomic number.

Mass and Atomic Number

• Atomic number is the number of protons in an atom; it defines the element.
• Mass number is the total number of protons and neutrons in an atom.
• Using atomic number and mass number, the number of neutrons in an atom can be calculated.

Electron Arrangement

• Electrons orbit the nucleus in specific energy levels called electron shells.
• The arrangement of electrons determines the chemical properties of an element.
• Valence electrons are electrons in the outermost shell and influence how an element will bond with others.

Periodic Table

• The periodic table organizes elements based on their properties.
• The number of valence electrons correlates with the element's group on the periodic table.

Ions

• Ions are atoms that have lost or gained electrons, giving them a net positive or negative charge.
• Metals lose electrons to form positive ions called cations.
• Nonmetals gain electrons to form negative ions called anions.
• Ions form when atoms need to fulfill a stable octet rule or other rules.

Electron Shell Diagrams

• Electron shell diagrams visually represent the arrangement of electrons in different energy levels around the nucleus.

Calculating Ion Charge

• The charge of an ion can be calculated by comparing the number of protons and electrons.

Ionic Compound Formation

• Ionic compounds form when metals react with nonmetals.
• The metal loses electrons, forming a positive cation, and the nonmetal gains electrons, forming a negative anion.
• The electrostatic attraction between these oppositely charged ions forms the ionic bond.

Chemical Formulae

• Chemical formulas represent the composition of ionic compounds.

Test your knowledge on the fundamental concepts of chemistry, including elements, compounds, mixtures, subatomic particles, isotopes, and atomic structure. This quiz covers key definitions and principles that are essential for understanding matter at the atomic level.