Period 3 Flashcards
- Reactions of Period 3 elements. - The oxides of elements in Period 3. - The acidic/basic nature of the Period 3 oxides. - Practice questions.
What are the elements in Period 3?
Na, Mg, Al, Si, P, S, Cl and Ar.
From left to right across the period…
you go from metals to non-metals.
Is Si a metal or non-metal?
It is a semi-metal and therefore can conduct small amounts of electricity.
Argon is a noble gas. True or false?
True!
What type of reaction do all Period 3 elements undergo?
Redox reactions. This is because the elements always start with an oxidation state of 0.
How does sodium react with water?
Vigorously.
How does magnesium react with water?
Slowly.
How does magnesium react with steam?
Vigorously.
What is the oxidation state of an element?
0.
The sum of the oxidation states should be…
The same on either side of the equation.
How do metals react with oxygen?
They burn vigorously to form basic oxides.
How do non-metals react with oxygen?
They burn to form acidic oxides.
Is silicon dioxide soluble or insoluble?
Insoluble.
How do you react sodium, Na, with oxygen?
Place hot sodium in a gas jar of oxygen.
How do you react magnesium, Mg, with oxygen?
Place burning magnesium ribbon in a gas jar of oxygen.
How do you react aluminium, Al, with oxygen?
Sprinkle aluminium powder into a Bunsen flame.
Why does aluminium appear unreactive to air or water?
It is coated with a thin but tough layer of oxide which protects it. Once scratched, the aluminium is so reactive that a new layer of oxide forms immediately.
What is an allotrope?
The term allotrope refers to one or more forms of a chemical element that occur in the same physical state. For example: graphite and diamond are allotropes of carbon.
How many allotropes does phosphorus have?
Two - one red, one white. (White phosphorus will spontaneously ignite in air).
What colour are metal oxides?
They are white as the metals have no part-filled d-orbitals (see the topic “Coloured Ions”).
