Periodic Table Lesson

Periodic Table

Concept 1: Elements are the building blocks of matter

Periodic Table

• Elements are the building blocks of matter.

• Elements can be organized by their properties.

Periodic Table

• The modern periodic table organizes elements in groups and periods.

• Elements are classified as metals, non-metals, or semi-metals(metalloids).

Elements

• The basic building blocks of matter

• Made up of one type of atom (cannot be broken down further)

• About 90 elements occur naturally (carbon, silver, oxygen)

• Some elements are synthesized in labs

• Have varying properties

Copper

• Use by many indigenous cultures for art and tools as it is malleable and can be forced into different shapes

• Copper is an excellent conductor of heat and electricity

• It works great for water and gas pipes as well as electrical wiring

Elements: Names and Symbols

• Chemical name: based on Latin words, countries, names of famous scientists

• Chemical Symbols: one or two letters (first letter is capitalized)

• Synthetic or unnamed elements have placeholder names or three-letter symbols

Concept 2: Elements can be organized by their properties.

1860s: Dmitri Mendeleev

• Russian teacher and chemist

• Looked at different ways to organize the elements

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1860s: Dmitri Mendeleev

• Wrote properties of elements on cards so that he could rearrange them and compare properties (“chemical solitaire”)

• Properties included atomic mass (average mass of an atom of an element), density, and melting point

Mendeleev’s periodic table

• Ordered the elements by increasing atomic mass

• Grouped elements into “families” based on similar properties (density, melting point) 

The Predictive Power of Mendeleev’s Table

• Left gaps in his periodic table to predict the existence of elements not yet found

• These missing elements would have properties similar to other elements in the same families

Concept 3: The modern periodic table organizes elements in groups and periods.

Modern Periodic Table

• Mendeleev’s periodic table was ordered by increasing atomic mass

• Did not work perfectly – some elements were out of order so they would fit in a family that had similar properties

• Modern periodic table is ordered by increasing atomic number

Modern Periodic Table

• Henry Moseley: scientist that determined an element’s atomic number (the number of protons in an atom)

• When elements are arranged according to increasing atomic number, the elements fit perfectly and do not require re-ordering

The modern periodic table consists of

• Groups (1-18): A vertical column of elements; also called a family

• Periods (1-7): A horizontal row of elements

Multiple Select

What is the chemical symbol and atomic number of Vanadium?

• 23

• Va

• 25

• V

• 30

Multiple Select

What is the chemical name and atomic number of "Pt"

• Palladium

• Plantium

• Platinum

• 80

• 78

Multiple Select

Where can Sulfur be found on the periodic table? (choose the period and group)

• Period 5

• Group 16

• Period 4

• Group 11

• Period 3

Concept 4: Elements are classified as metals, non-metals, or semi-metals.

Three broad categories of elements shown on the periodic table

• Metals (yellow)

• Non-metals (green)

• Semi-metals(metalloids) (purple)

Main-Group and Transition Elements

• Elements of Groups 1, 2, and 13 to 18 are called main-group elements or representative elements

• Elements in Groups 3 to 12 are called transition elements

Metals

• Shiny and hard (typically)

• Malleable and ductile (can be made into sheets and drawn out into wires)

• Conducts electricity and heat

• Found to the left of the zigzag line on the periodic table

Metals: Alkali Metal

• Found in Group 1 (all elements, except hydrogen)

• Shiny and soft

• Highly reactive with water and oxygen (often stored in a non-reactive liquid such as oil)

https://www.youtube.com/watch?v=dmcfsEEogxs

Metals: Alkaline-earth Metals

• Found in Group 2

• Shiny and soft (but not as soft as alkali metals)

• Highly reactive (but not as reactive as alkali metals)

Non-metals

• Not shiny, malleable, or ductile

• Poor conductors of electricity and heat

• Found to the right of the zigzag line on the periodic table

• Generally gases or brittle, dull solids

Non-metals: Hydrogen

• Usually on the left side of the periodic table

• Lightest element

• Colourless, odourless, tasteless

• Highly flammable

• Makes up over 90% of atoms in the universe

Non-metals: Halogens

• Found in Group 17

• Highly reactive (therefore usually found in nature as part of compounds)

Non-metals: Noble Gases

• Found in Group 18

• Odourless, colourless gases

• Least reactive of all of the elements

• Helium and neon never form compounds; The others will form compounds with great difficulty

Semi-metals

• Also known as metalloids

• Found in the green boxes in a staircase shape

Semi-metals

• Have physical and chemical properties of both metals and non-metals

• Shiny (like metals)

• Brittle and not ductile (like non-metals)

• Poor conductors of heat and electricity (like non-metals)

Semi-metals: Silicon

• Second-most abundant element in Earth’s crust (after oxygen)

• Used in many electronic devices (computers, smartphones)

• Used to make silicone (material used in cookware, contact lenses, prosthetics)

Multiple Select

What characteristics define metals?

• poor conductors of heat and electricity

• shiny

• can form sheets and wires

• conduct heat and electricity well

• dull and brittle

Multiple Select

What characteristics define non-metals?

• dull

• shiny

• brittle solids or gases

• poor conductors

• make good electrical wiring

Multiple Choice

What group would we find the most reactive metals?

• Halogens

• Alkaline earth metals

• Transition metals

• Alkali metals

• Noble gases

Multiple Choice

What group would be find the least reactive elements?

• Transition metals

• Group 8

• Alkali metals

• Noble Gases

Multiple Select

What characteristics define semi-metals?

• conduct heat and electricity well

• shiny

• poor conductors

• brittle

• malleable