Periodic

Quizizz Lesson Unit 6 Lesson 4: Periodic Trends

While there were several scientists at the time attempting to organize the known elements, Dimitri Mendeleev is mostly credited with creating a table that led to our modern approach. ​

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Dimitri Lived from 1834 - 1907.

Creator of the periodic table

What made his table famous was that it was created around the idea that elements had periodically repeating patterns in behavior. Hence the name periodic table.

Because of this he was even able to predict some properties of previously undiscovered elements. His predictions turned out correct. ​

Dimitri created his model of the periodic table in 1872

Creator of the periodic table

While we learned how the periods mimic electron configuration what we also know is that elements in the same groups often have very similar properties. Some of these groups have properties so similar we give them special names. Above are 5 common groups or families we will look at further. ​

Arrangement of the Periodic Table​

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​​The current periodic table is made up of 7 Periods or rows and 18 Groups or columns.

Fill in the Blank

What element is located at period 3 group 13?

So group 1 elements known as the Alkali Metals are so-called because when they react with water, they create highly alkaline substances

An alkaline substance is another term for Basic. or the opposite of an acid.

Arrangement of the Periodic Table​

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Group 2 elements known as the Alkaline Earth Metals are given this name because prior to the 19th century, substances that were nonmetallic, insoluble in water, and unchanged by fire were known as earths. But these metals also resembled the basic nature of the alkali metals.

Arrangement of the Periodic Table​

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Group 3-12 elements are known as the Transition Metals are so-called because they oxidation state or predicted ionic charge can change or transition. This means that depending on the substance they are reacting with or the compound they are found present in they are "giving away" a different number or electrons.

Often times these different transition states in compounds produces varying colors that are extremely diverse as well.

Arrangement of the Periodic Table​

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Match

Match the following metals with their family name.

• Cobalt

• Calcium

• Cesium

Transition Metal

Alkaline Earth Metal

Alkali Metal

• Transition Metal

• Alkaline Earth Metal

• Alkali Metal

Group 17 elements are known as the Halogens. These are the first family of nonmetals given a common name. Halogens are given this name because they are known as salt formers. Any compound that begins with a metal and ends with a halogen is a salt with a crystal lattice structure.

Halogens are also well known as strong oxidizers so are used for their antiseptic properties.

Arrangement of the Periodic Table​

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Open Ended

Think about water and look at the possible halogens. Describe one way that halogens are used to clean or disinfect water for humans.

Finally Group 18 elements are known as the Noble Gases. These are a family of nonmetals known for their inability to react or mix with other substances.

They are oftentimes called inert gases as well. We use them to fill items such as light bulbs where we don't want oxidation to occur on the metal filament or combustion to be promoted.

Arrangement of the Periodic Table​

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The table is full of other periodic trends as well. We are going to take a look at just a few. Some help explain the behavior of elements and bonding.

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Periodic Trends

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The first trend we want to look at is atomic radius. This more or less allows us to predict the size of an atom.

​Atoms get larger as you go down the table. This trend is easy and makes sense because each additional period down a table represents a new electron orbital on an atom.

Atomic Radius

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The second part of this trend is tricky. Elements get larger as you move left on the table.

This can seem counterintuitive at first. This means that atoms are getting larger even though they have fewer protons and electrons. You would think as mass increases so does size. ​

Atomic Radius

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The reason for this is because with fewer electrons in the outermost shell there is less attraction to the positively charged nucleus. This allows this shell to spread out. (Remember an atom is mostly empty space)

I think of the last shell like a belt that squeezes everything in.​

Atomic Radius

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Reorder

Reorder the following elements from smallest largest.

• Sodium (11)

• Gallium (31)

• Calcium (20)

• Tin (50)

• Strontium (38)

1

2

3

4

5

• 1
• 2
• 3
• 4
• 5

Electronegativity increases as atoms get smaller. This means there are fewer electrons blocking the nucleus from pulling on new electrons. (inner shell shielding)

So basically electronegativity increases towards the top and right side of the table.

Most noble gases have no electronegativity as their valence shell is full

​ELECTRONEGATIVITY

The final trend we are going to look at is reactivity. Chemical reactivity can be tricky because it is different for metals and nonmetals. Chemical reactivity is caused by the other trends. Really you can start to see that all trends occur because of similarities.

Reactivity

All ​elements are more reactive towards the edges of the table*. So column 1 metals are more reactive than column 2 metals and so on. But metals become more reactive towards the bottom of the table. This is because the elements are larger. This means the nucleus has less pull on these outside valence electrons and they are allowed to be lost easier causing this reaction.

Reactivity

All ​elements are more reactive towards the edges of the table* but in nonmetals we must remember that noble gases are not reactive at all. So the most reactive nonmetals are the halogens. Nonmetals are also more reactive towards the top of the table. This is because they are smaller meaning the nucleus has less in the way as it tries to steal electrons from other atoms causing the reaction.

Reactivity

Open Ended

In the video we watched earlier Cesium metal was an extremely reactive substance, what would be an extremely reactive nonmetal based on the trend we just learned?

Elemental Families

Atomic Radius

Reactivity

Electronegativity

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Summarize

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Multiple Choice

What elemental family is the element Iodine found?

• Alkaline Earth Metals

• Halogens

• Noble Gas

• Alkali Metals

Multiple Choice

Which of these elements would you predict to have a higher electronegativity?

• Phosphorus

• Silicon

• Nitrogen

• Oxygen

Multiple Choice

Which element would you predict to have the largest radius?

• Sodium

• Magnesium

• Calcium

• Potassium

Multiple Choice

Which element would you predict to be the most reactive

• Sodium

• Magnesium

• Calcium

• Potassium

Multiple Choice

Which of the following elements would you predict to be the most reactive?

• Bromine

• Chlorine

• Sulfur

• Selenium

Labelling

Label the families of the periodic table.

Drag labels to their correct position on the image

Halogens

Acidic Metals

Common Gases

Stationary Metals

Transition Metals

Pnictogens

Noble Gases

Chalcogens

Alkaline Earth Metals

Alkali metals