The Periodic Table - Year 10

In what order did Mendeleev put the elements?

• Order of increasing atomic weight

• Order of increasing mass number

Why did he not stick to this order for some elements?

• To ensure that elements were in periods with other elements with similar properties

• Some were still undiscovered.

• To ensure that elements were in groups with other elements with similar properties.

Why did Mendeleev leave some gaps in his table?

• He didn't want to finish it.

• He predicted that some elements had yet to be discovered.

• He died before he could finish it.

Give three ways in which today's Periodic Table is different from Mendeleev's table.

• Elements arranged in order of atomic number instead of atomic weight

• Actinides and lanthanides are not present – but were in Mendeleev’s table

• Noble gases present – none in Mendeleev’s table

• No gaps and more elements in today’s Periodic Table

Element 1 makes a ringing sound when struck and is used in electrical cabling. Is this a metal or a non-metal?

• Metal

• Non-metal

Element 2 is a gas which does not conduct electricity. Is this a metal or a non-metal?

• Metal

• Non-metal

Element 3 is a yellow solid at room temperature that easily melts when warmed. Is this a metal or non-metal?

• Metal

• Non-metal

Element 4 is a solid that conducts heat very well and can be hammered into shape to make saucepans. Is this a metal or a non-metal?

• Metal

• Non-metal