Chemistry - Chapter 2 - Atoms and bonding

What does a Period show?

It shows how many shells an element has.

What does a Group show?

It indicates the number of valence electrons in an atom.

What is Sublimation?

When Solids turn straight into Gases.

What is Deposition?

When Gases turn straight into Solids.

What is the Radius of an Atom?

1 × 10^-10

What is the Radius of a Nucleus?

1 × 10^-14 m

What are Ions?

Charged Atoms, + or -

What is the Ion number for Group 1?

+1

What is the Ion number for Group 2?

+2

What is the Ion number for Group 3?

+3

What are the Ion numbers for Group 4 and 5?

They do not form Ions.

What is the Ion number for Group 6?

-2

What is the Ion number for Group 7?

-1

What is the Ion number for Group 8/0?

Nothing, they are Stable.

Why is the e- sometimes put on the left or right?

If its on the left it means the electrons are being captured and if its on the right the electron is being ejected.

(For example, Na→ Na+ + 1e-       F + 1e- → F-

What is an Electrostatic Force?

Forces of attraction between positive and negative ions.

Why do Ionic compounds only conduct when melted or dissolved?

There are no delocalised electrons in the solid form (every ion has a full outer shell), when they are dissolved in water ions become mobile.

Properties of Monatomic Structure:

1. Very Low M&B points;

2. Does not conduct as a solid;

3. Does not conduct when melted;

4. Insoluble in water;

5. Solution does not conduct (insoluble);

Properties of Ionic Structures:

1. High M&B points;

2. Does not conduct as a solid;

3. Conducts when melted;

4. Soluble (usually) in water;

5. Solution conducts;

Properties of Simple Molecular Structures:

1. Low M&B points;

2. Does not conduct as a solid;

3. Conducts when melted;

4. Insoluble (usually) in water;

5. Solution does not conduct (insoluble);

Properties of Giant Covalent Structures:

1. Very High M&B points;

2. Some do and some do not conduct as a solid;

3. Does not conduct when melted;

4. Insoluble in water;

5. Solution does not conduct (insoluble);

Properties in Metallic Structures:

1. High M&B points;

2. Conducts as a solid;

3. Conducts when melted;

4. Insoluble in water;

5. Solution does not conduct (insoluble);

What is a Giant Ionic Lattice?

A structure that Ionic Compounds form (square).

How are the Giant Ionic Lattice arranged?

With positive ions next to the negative ions because of the strong electrostatic forces between them.

What is ionic bonding in terms of oppositely charged ions?

Ionic bonding is the electrostatic attraction between oppositely charged ions, which occurs when the valence (outermost) electrons of one atom are transferred permanently to another atom.

What is covalent bonding in terms of shared pairs of electrons?

Covalent bonding involves the sharing of electron pairs between atoms. These bonds are characterized by the sharing of one or more pairs of electrons, which allows each atom to attain a stable electronic configuration.

What is metallic bonding in terms of delocalised electrons?

Delocalized electrons in metallic bonding are free-moving electrons that are shared among a network of positively charged metal ions, contributing to the unique properties of metals.

What are the three limitations of dot and cross diagrams for representing giant ionic lattices?

1. Not 3D

2. Can not see bond strength

3. No inner shells

What are the three limitations of ball and stick diagrams for representing giant ionic lattices?

1. Inaccurate ion sizes

2. Misrepresentation of bond lengths

3. Does not show continuous ionic network

What are the three limitations of 2D diagrams for representing giant ionic lattices?

1. Not 3D

2. Misrepresentation of ionic layers and spacing

3. Does not show bonding strength and forces

What are the three limitations of 3D diagrams for representing giant ionic lattices?

1. Oversimplification

2. Scale distortion

3. Lack of dynamic information

What are the limitations of Dot-and-Cross Diagrams for Molecules?

1. Not 3D
2. Do not show actual bond angles or shapes
3. Do not show relative sizes of atoms

What are the limitations of Ball-and-Stick Diagrams for Molecules?

1.  Bond lengths may be inaccurate.

2. Ball sizes are unrealistic.

3. Bonds are exaggerated and do not show electron density

What are the limitations of 2D Structural Formulae for Molecules?

1. Not 3D (cannot show true molecular geometry)

2. Can misrepresent bond angles

3. Does not show electron distribution or polarity

What are the limitations of 3D Models for Molecules?

1. Oversimplification of electron density
2. Static models do not show movement (rotation, vibration)
3. Scale distortion between atoms and bonds

What are the limitations of Dot-and-Cross Diagrams for Giant Structures (covalent or metallic)?

1. Not 3D
2. Cannot show extended network structure
3. Do not show bond strength or delocalised electrons

What are the limitations of Ball-and-Stick Diagrams for Giant Structures?

1. Inaccurate spacing and scale
2. Misrepresents number of bonds per atom
3. Cannot show the continuous giant lattice (only a small section)

What are the limitations of 2D Diagrams for Giant Structures?

1. Not 3D and cannot show depth of lattice
2. Misrepresentation of repeating units
3. Does not show bonding forces or electron delocalisation

What are the limitations of 3D Models for Giant Structures?

1. Oversimplified repeating units
2. Scale distortion between atoms and lattice spacing
3. Cannot show dynamic behaviour (vibrations, electron movement)