Question

Period 3 contains the elements sodium to argon.

      Na           Mg            Al        Si            P        S            Cl       Ar

1.1 Give the element that has the largest atomic radius in Period 3.                             [1]

 

 

1.2 Sodium is a reactive metal.

1.2.1 Describe one physical property of sodium.                                                            [1]

 

 

1.2.2 Write down the electronic configuration of the sodium ion.                                   [1]

 

 

1.2.3 Give one observation when sodium reacts with cold water.                                  [1]

 

 

1.2.4 State the flame colour of sodium.                                                                          [1]

 

 

1.3 Magnesium reacts slowly with warm water to form a base, magnesium hydroxide.

1.3.1 Define a base in terms of proton transfer                                                              [1]

 

 

1.3.2 Suggest the pH of magnesium hydroxide and give the colour of universal Indicator                                                                                                                 

                                                                                                                                        [2]

pH colour of universal indicator

 

1.3.3 Magnesium hydroxide can be used to treat indigestion by reacting with stomach

        acid. State the type of reaction this is.                                                                    [1]

 

 

1.4 Aluminium combines with oxygen to form aluminum oxide.

      Name the type of oxide aluminium oxide forms.                                                       [1]

 

 

1.5 Silicon dioxide has a giant structure.

1.5.1 Name the type of bonding in silicon dioxide.                                                         [1]

 

 

1.5.2 Give one physical property of silicon dioxide.                                                        [1]

 

Answer 1

Here are the answers to your questions regarding elements in Period 3:

1.1 **Give the element that has the largest atomic radius in Period 3.**
**Answer:** Sodium (Na)

1.2 **Sodium is a reactive metal.**
1.2.1 **Describe one physical property of sodium.**
**Answer:** Sodium is a soft metal that can be easily cut with a knife.

1.2.2 **Write down the electronic configuration of the sodium ion.**
**Answer:** The electronic configuration of the sodium ion (Na⁺) is 1s².

1.2.3 **Give one observation when sodium reacts with cold water.**
**Answer:** Sodium fizzes and floats on the surface of water while forming bubbles of hydrogen gas.

1.2.4 **State the flame colour of sodium.**
**Answer:** The flame colour of sodium is bright yellow.

1.3 **Magnesium reacts slowly with warm water to form a base, magnesium hydroxide.**
1.3.1 **Define a base in terms of proton transfer.**
**Answer:** A base is a substance that accepts protons (H⁺ ions) in a chemical reaction.

1.3.2 **Suggest the pH of magnesium hydroxide and give the colour of universal Indicator.**
**Answer:**
pH: Approximately 10-11
Colour of universal indicator: Blue to purple

1.3.3 **Magnesium hydroxide can be used to treat indigestion by reacting with stomach acid. State the type of reaction this is.**
**Answer:** This is a neutralization reaction.

1.4 **Aluminium combines with oxygen to form aluminum oxide. Name the type of oxide aluminium oxide forms.**
**Answer:** Aluminium oxide forms an amphoteric oxide.

1.5 **Silicon dioxide has a giant structure.**
1.5.1 **Name the type of bonding in silicon dioxide.**
**Answer:** The type of bonding in silicon dioxide is covalent bonding.

1.5.2 **Give one physical property of silicon dioxide.**
**Answer:** Silicon dioxide is hard and has a high melting point.

Feel free to ask if you need further clarification or additional questions!