Unit 2- bonding, structure and properties of matter Flashcards
In solids what are the three main features of the particles?
Have a regular arrangement
Are very close together
Vibrate about fixed positions
In liquids what are the three main features of the particles?
Have a random arrangement
Are close together
Flow around each other
In gases what are the three main features of the particles?
Have a random arrangement
Are much further apart
Move very quickly in all directions
Name 3 limitations of the particle model
- Forces between particles are not shown
- The volume of the particles
- The space between the particles
Can liquids be compressed?
No❌❌❌❌❌
What 3 things occur when a substance changes state
The particles themselves stay the same
The way the particles are arranged changes
The way particles move changes
The amount of energy required required for a substance change to state depends on?
The amount of energy required to overcome the forces of attraction between the particles
The stronger the forces of attraction?
The greater amount of energy needed to overcome them
The higher the melting points due to strong bonds
What are 3 substances that have high melting points due to the strong bonds
Ionic compounds
Metals
Giant covalent structures eg diamond 💎
In substances that contain small molecules ? 3 points
The bonds within the molecules are strong covalent bonds
The forces of attraction between the molecules are much weaker
Only a little energy is needed to overcome the forces between the molecules
What is an ion
An atom that has gained or lost an electron
Ionic bonding occurs between what?
Metals and none metals
Positive and negative ions
Ions have a complete?
Outer shell of electrons (the same as noble gases)
In ionic bonding, the metal ?
And the none metal?
The metal loses electrons to become positively charged ions
The none metal gains electrons to form a negatively charged ion
What is an ionic bond
The strong electrostatic force of attraction between a positive metal and a negative none metal
State 4 things about ionic compounds
- High melting and boiling point
- Do not conduct electricity when a solid, because ions cannot move
- Do conduct electricity when molten or in a solution because the ions are free to move about and carry their charge
- Dissolve in water
Where does covalent bonding occur?
Between non metals
What can be used to show covalent bonds
A dot and cross diagram
Covalent bonds are very strong true or false?
True✅✅
What is a covalent bond
A shared pair of electrons between atoms
Can small molecules conduct electricity?why
No because they have no overall charge