- The periodic table is a chart that shows the elements known to man.
- Dmitri Mendeleev was the Russian chemist who began organizing the table in 1869, arranging elements by increasing atomic weight.
- An atom is the smallest unit of matter, composed of protons, neutrons, and electrons.
- Elements are pure substances with unique properties; they have one type of atom and cannot be broken down further.
- Similar elements include carbon, oxygen, hydrogen, and nitrogen; other materials like salt or water are compounds made from multiple elements.
- Of the 118 known elements, 24 are found in nature; the rest are synthetic.
- Mendeleev grouped elements into groups (columns) and periods (rows), with each group sharing similar chemical properties.
- Groups are numbered 1–18; periods are numbered 1–7, with increasing atomic number and atomic weight from left to right.
- Elements are categorized as metals, nonmetals, metalloids, transition metals, and noble gases.
- Metals are labeled and located on the left side of the table; examples include copper, zinc, boron, carbon, oxygen, fluorine, and helium.
- Nonmetals are located on the right side; examples include silicon, sulfur, phosphorus, and aluminum.
- Metalloids are located between metals and nonmetals; examples include arsenic, antimony, and tellurium.
- Transition metals are located in the middle; examples include iron, cobalt, nickel, and copper.
- Noble gases are located on the far right; examples include helium, neon, argon, krypton, xenon, and radon.
- There are four blocks: s-block, p-block, d-block, and f-block.
- The s-block includes groups 1 and 2; the p-block includes groups 13–18; the d-block includes groups 3–12; the f-block includes the lanthanides and actinides.
- Atomic number is the number of protons in an atom’s nucleus.
- Atomic mass is the average mass of an atom’s isotopes.
- Ionization energy is the energy required to remove an electron from an atom.
- Electronegativity is the strength of an atom’s ability to attract electrons.
- Electron affinity is the energy change when an atom gains an electron.
- Metallic character refers to how easily an element can lose electrons.
- There are eight periods (rows) on the periodic table.
- Elements are labeled and numbered 1 through 118.
- There are 18 groups (columns) on the chart.
- The periodic table helps predict element properties and reactivity.
Parent Tip: Review the logic above to help your child master the concept of reading the periodic table worksheet.
