Periods are the horizontal lines in the periodic table. You can remember them by thinking about how you write sentences horizontally with periods.  Elements in the same period have the same amount of energy shells. In the Periodic Table, there are seven periods. The two rows at the bottom fit into the 6th and 7th periods. As you move to the right of a period, the atom gets another proton and electron, meaning the atomic number increases across the period.

Periods

Families

Also known as families, groups are the vertical lines in the periodic table. There are 18 groups in total. Elements in the same family have very similar chemical properties. Elements in groups also react and bond to other atoms the same, as each group has the same number of valence electrons (besides the transition metals).

Protons

Protons are located in the center of the atom, called the nucleus. When you talk about the atomic number, you’re talking about the number of protons in the number. For example, if an element has 2 protons, we know the element is Helium, and the atomic number is 2. The number or protons increases as you move across the periodic table. Protons have a positive charge. Protons make up part of the atomic mass of the atom.

Neutrons

Neutrons are also located in the nucleus. They don’t have a charge, but they help stabilize the atom. Without neutrons, the atom would be unstable. The neutron is also part of the atomic mass.

Electrons

Electrons are located in the orbital shell of the atom. They have a negative charge, and barely have any atomic mass. When atoms combine to form a molecule, that’s because they share electrons.

Valence Electrons

Valence electrons are the electrons in the outermost shells. Atoms that are in the same family have the same number of valence electrons and the same amount of reactivity. Having a complete outer shell means that the electrons probably won’t bond with another atom. The first shell can hold 2 electrons and the second shell can hold 8 electrons. The first family is the most reactive, since they want to get rid of their one electron. The 18th group isn’t reactive because they have a complete outer shell.

Atomic Radius

As you go down the period (period one, period two), the atomic radius of an atom increases. That because as you go down a period, they get an extra shell. This means that the atomic radius is largest at the start of a period. As you go through the period, such as from the first family to the second, the atomic radius increases. This is because the pull from the nucleus (the proton and electron have opposite charges) pulls the electrons closer towards the nucleus.

Element Cards

APE MAN

APE MAN is an easy way to remember atomic number and atomic mass.

Atomic number is the number of

Protons or

Electrons

Mass number

-Atomic number (number of protons)

=Number of neutrons

Because the atomic mass is the number of protons and neutrons, you can take the mass number and minus it by the atomic number (number of protons) to get how many neutrons there are in an atom.

How the Periodic Table is Arranged

Metals

Metals consist of Alkali metals, Alkaline Earth metals, Lanthanoids, Actionoids, Transition metals, and Post-Transition metals. They are the largest out of metals, metalloids, and nonmetals, and are located to the left of the periodic table.. Most metals are solid at room temperature, with the exception of Mercury, and are excellent conductors of heat and electricity. They are malleable (easily made into thin sheets) and ductile (can be made into thin wires). Metals have high melting and boiling points and are lustrous. 

Metalloids

Metalloids are the staircase of the periodic table. They’re a cross of nonmetals and metals, having some properties of each. They can conduct electricity, but not very well (this makes them valuable with the computer chip industry). All metalloids are solid at room temperature and some are lustrous. Some metalloids are brittle, and some metalloids are malleable or ductile.

Non-Metals

Non-metals consist of the Reactive Nonmetals and the Noble Gases. The only Nonmetal that’s not on the right side of the periodic table is Hydrogen. They’re the opposite of metals, being brittle and are poor conductors of heat and electricity.  Most nonmetals are either a gas or a solid at room temperature. Only Bromine is a liquid at room temperature. They’re in various colors, and aren't shiny. 

Lithium

Sodium

Potassium helps make fertilizers.

Alkali Metals

The Alkali metals make up the first group of the periodic table. They are the most reactive metals, as they only have one valence electron. They try their hardest to get rid of that one extra electron. Alkali metals are soft and shiny metals with high ductility. They are excellent conductors of heat and electricity. Lithium is the lightest metal element. Three Alkali metals are Rubidium, Caesium, and Francium. Sodium is used for making things like table salt (NaCl) and baking soda (NaHCO3). Lithium is used to make light-weight batteries. These batteries are used in cameras and pacemakers.

Beryllium

Magnesium

In the aviation industry, Beryllium is used for the cogs and gears.

Alkaline Metals

The Alkaline Earth metals make up the second group of the periodic table. They are good conductors of electricity and they’re either silvery white or gray. They’re shiny and have low densities, and low melting and boiling points. They all have 2 valence electrons, so they’re very reactive but not as reactive as the Alkali metals. They want to get rid of their two valence electrons. Strontium, Barium, and Radium are all Alkaline Earth metals. Calcium carbonate (CaCO3) is used to make cement and mortar. Strontium illuminate (SrAI2O4) is used to make glow-in-the-dark paints and can also make some plastics.

Scandium

Zinc

Vanadium is used to make nuclear reactors.

Transition Metals

Transition metals are from groups 3-12 and make up 32% of the periodic table. The properties of transition metals varies a lot, but they all have high densities and high melting/boiling points. They are good conductors of heat and electricity, and are malleable and ductile. Most of them are hard, silvery white, and lustrous. When transition metals form compounds with other elements, they become very colorful. Some examples of transition metals include Technetium, Tungsten, and Platinum. Cobalt is used to make airbags in cars and drying agents for paints. Mercury is used to make thermometers and other scientific instruments.

Boron

Aluminum

Aluminum is used in parts of airplanes.

Boron Family

Elements in the Boron family are in the 13th group in the periodic table, and have 3 valence electrons each.  No elements were in their pure state before modern technology. Only after you could isolate these atoms, could you see they were separate elements. Gallium, Indium, and Thallium are some elements in this group. Boron is used to increase the hardness in steel, and in the semiconductor industry, Boron is added to Silicon and Germanium to modify electrical conductivity. Indium Tin Oxide is a very important part in making touch screens and solar panels.