Y8 - C4 The Periodic Table

Y8 - C4 The Periodic Table

​Learning Objectives

• ​KNOW IT - Know the key words and definitions for this topic

• ​THINK IT - Describe how the modern periodic table was developed

• ​

• GRASP IT - Explain the ​trends in reactivity for Group 1 and 7.

Atoms, Elements and Compounds​

• ​Atoms - The smallest particle (i.e an Oxygen atom)

• ​Elements - A substance made from only one type of atom

• ​Molecule - Two or more atoms bonded together (i.e O₂)

• ​Compounds - Two or more atoms of different types bonded together (ie H₂O)

Multiple Choice

What is the definition for a compound?

• The smallest particle (i.e an Oxygen atom)

• A substance made from only one type of atom

• Two or more atoms bonded together (i.e O₂)

• Two or more atoms of different types bonded together (ie H₂O)

Multiple Choice

What is the definition for an element?

• The smallest particle (i.e an Oxygen atom)

• A substance made from only one type of atom

• Two or more atoms bonded together (i.e O₂)

• Two or more atoms of different types bonded together (ie H₂O)

Multiple Choice

What is the definition for an atom?

• The smallest particle (i.e an Oxygen atom)

• A substance made from only one type of atom

• Two or more atoms bonded together (i.e O₂)

• Two or more atoms of different types bonded together (ie H₂O)

Multiple Choice

What is the definition for a molecule?

• The smallest particle (i.e an Oxygen atom)

• A substance made from only one type of atom

• Two or more atoms bonded together (i.e O₂)

• Two or more atoms of different types bonded together (ie H₂O)

​The development of the periodic table

​Dalton - Ordered elements by atomic mass, used symbols.

​

​Newlands - Ordered elements by atomic mass, Discovered that every 8th element was similar so he put the elements in 8 groups (law of octaves). But he ended up with some of the elements in groups with elements with different properties.

​

​Mendeleev - Ordered elements by atomic mass. Kept the 8 groups but swapped some elements around so they are in the correct groups. Left gaps for undiscovered elements and predicted their properties

​Modern Periodic Table

Multiple Choice

How did Dalton organise the elements in periodic table?

• Atomic numer

• Metals and Non-metals

• Atomic mass

• Reactivity

Fill in the Blanks

Newlands came up with the law of

Poll

Which scientist made the most important discovery?

• Dalton

• Newlands

• Mendeleev

• Dr Ahmed

Fill in the Blanks

Mendeleev improved the periodic table by leaving

for undiscovered elements

Fill in the Blanks

Mendeleev also predicted the

of the undiscovered elements

Multiple Choice

How is the modern day periodic table organised?

• Atomic numer

• Metals and Non-metals

• Atomic mass

• Reactivity

​Physical and Chemical Properties

• ​Physical

  • ​Density

  • ​Boiling / Melting point

  • ​Appearance

  • ​Solubility​

• ​Chemical

  • ​Reactivity

• ​

​Group 1 - The Alkali Metals

• ​React with water to make an alkali and hydrogen gas

• ​Have 1 electron in the outer, therefore want to LOSE 1 electron.

• ​Down the group the atoms get bigger, so the nuclear pull is less

• ​Down the group there is MORE shielding, so the nuclear pull is less

• ​Therefore down the group it is EASIER to LOSE the electron

​Group 7 - The Halogens

• ​Have 7 electron in the outer, therefore want to GAIN 1 electron.

• ​Down the group the atoms get bigger, so the nuclear pull is less

• ​Down the group there is MORE shielding, so the nuclear pull is less

• ​Therefore down the group it is HARDER to GAIN the electron

Multiple Select

Which are properties of metals?

• Sonorous

• Soft

• Dull

• Malleable

Open Ended

Write a physical property of most metals

Fill in the Blanks

Down group 1 the metals get

reactive

Fill in the Blanks

Down group 7 the halogens get

reactive

Multiple Choice

Down a group atoms become

• Bigger

• Smaller

Multiple Choice

Down a group shielding ...

• Increases

• Decreases

Open Ended

Explain why down group 7 elements get less reactive.