Atom Periodic Table Review

​ Atomic Particles

The atom is made from 3 main particles.

Proton - positive charge found in nucleus

Neutron - no charge found in nucleus

Electron - negative charge found outside nucleus.​

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The nucleus is the "brain" of the atom and has a positive charge. Most of the mass of an atom is found here.

The electrons surround the nucleus taking up a large amount of space in what we call the electron cloud. This is where most of an atom's volume is at.​

As new parts of the atoms were discovered, the models of the atoms were modified. you can see with the picture below the different models.

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Atomic Number

Every atom has a definite number of protons that identifies each atom like a finger print identifies people even identical twins.

The number of protons in each element is identified by the element's atomic number.​

​Mass Number

Every element is identified with a certain number of protons (this tells the atom what it is going to be - like your fingerprint) and a certain number of neutrons. These two particles added together make up the mass number.

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As you can tell Helium has a mass number of 4. If we subtract the Mass Number (protons + neutrons) 4. from the Atomic Number (protons) 2. 4-2 = 2 Then I know the element has a total of 2 neutrons. ​

Periodic Table

The Periodic Table is broken down into 2 main groups.

Columns and rows.

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Rows run left to right and the elements increase in their atomic number by 1 as you move from element to element. These rows are called PERIODS. Periods are numbered 1-7​ . A period in the picture to the left has a period circled in black.

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Do you see the periods on the periodic table to your left?

Columns​ on the periodic table run up and down. This is a group of elements that react very similar to each other. These elements also have the same number of electrons in their outer energy shell. These columns are called GROUPS. Groups are numbered 1-18 and the number is above each group. One group on the picture to the left is circled in red.

Some groups have been given names because of how they react with other elements or do not react at all with any other element.

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Periodic Table

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We look at groups 1-2, 13-18 for the number of electrons in the element. Group 1 has 1, 2 has 2, 13 has 3 and so on till you get to group 18. It has 8. Elements need 8 electrons in their outer shell to be considered stable.

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Groups

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Reactivity for

METALS​

Elements that are labeled as metals will increase in their reactivity with other elements as you move DOWN the group and move from RIGHT to LEFT on the period.

Metals are very important materials for us in so many ways. ​

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Metal properties

Metals are so important for us as we use them in everything we do every day. Not all metals are the same in every property. Some are better than others at certain things.

Metals have the ability to be shaped like we want them. This property is called malleability.

Metals also allow heat and electricity to flow through it evenly and quickly to allow us to cook our foods and have electricity in our houses. We call this property conductivity.​

Metals can be heated up and pulled into wires as thick or as thin as we need to to make electrical wires to run our houses and electronic devices. We call this property ductility.​

​Metals are also great at reflecting light off of them when the light hits it just right. We see this in some metals better than others like gold, silver, chrome, aluminum, and copper. This property is called luster.

Metals are solids at room temperature having a silvery appearance. Mercury is the only metal that is a liquid at room temperature.

Metals also have high densities, melting and boiling points. These properties increase as you move left to right on the periods of elements.

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Non-metals are different from metals. They may have some of the same similar properties but not all that make metals who they are.

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​Non-metals can be gas, liquid or solid. 

They aren't shiny (lustrous) and they don't conduct heat or electricity well but make great insulators which prevent heat or electricity from leaving.

Usually their melting points are lower than for metals, as with anything there are always exceptions.

Non-metals when they are a solid usually break easily, and can't bend like metal

​NON-METALS

​Metalloids

​Metalloids are the elements that separate the transition metals from the non-metals. These elements are knows as the "Stair Step" elements.

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Characteristic Properties of Metalloids

Metalloids are solids

They have a metallic luster, and generally look like metals

They are brittle, and easily shattered

Metalloids can conduct electricity, but not as well as metals.

Chemically, they act more like nonmetals

Group Names

As we said earlier, elements are grouped together when they share similar properties like reactivity similar densities and melting/boiling points. You can see by looking at the picture above, which elements are very reactive and those that are not. ​

The Alkali Metals are the most reactive of metals and the Halogens (only found as a compound in nature as salts) are the most reactive of nonmetals.​

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