Unit 1 - Chemical Changes & Structures Flashcards Preview

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Flashcards in Unit 1 - Chemical Changes & Structures Deck (25)
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1
Q

A very unstable arrangement of atoms formed at the maximum of the potential energy barrier, during a chemical reaction.

A

Activated Complex

2
Q

The minimum kinetic energy required by colliding particles before a reaction will occur, since high energy activated complex must be formed.

A

Activation energy

3
Q

Substance which increases the rate of reaction without being used up, often a transmission metal.

A

Catalyst

4
Q

The term used to describe the mechanism by which atoms are held together.

A

Chemical Bonding

5
Q

Describes the way in which atoms, ions or molecules, are arranged.

A

Chemical structure

6
Q

Of reactions suggests that, for a chemical reaction to occur, particles must collide.

A

Collision theory

7
Q

Formed when two atoms share electrons in their outer shell to complete the filing of that shell

A

Covalent bond

8
Q

Half the distance between the nuclei of two bonded atoms of an element.

A

Covalent radius

9
Q

Electrons, in metallic bonding, are free from attachment to any one metal ion and are shared amongst the entire structure.

A

Delocalised electrons.

10
Q

Molecules with only two atoms (e.g. oxygen, O2, and carbon dioxide, CO)

A

Diatomic molecules

11
Q

An atom or molecule in which a concentration of positive charges is separated from a concentration of negative charge.

A

Dipole

12
Q

A measure of the attraction that an atom involved in a bond has for the electrons of the bond.

A

Electronegativity

13
Q

The energy required to remove one mole of electrons from one mole of atoms in the gaseous state.

A

First ionisation energy

14
Q

Molecules of pure carbon constructed from 5- ad 6- membered rings combined into hollow structures. The most stable contains 60 carbon atoms in a shape resembling a football.

A

Fullerene

15
Q

Electrostatic forces of attraction between molecules containing a hydrogen atom bonded to an atom of a strongly electronegative element such as flourine, oxygen or nitrogen, and a highly electronegative atom on a neighbouring molecule.

A

Hydrogen Bonding

16
Q

They attract molecules together. They are weaker than chemical bonds.

A

Intermolecular forces

17
Q

Forces of attraction which exist within a molecule.

A

Intramolecular forces

18
Q

A regular 3D arrangement of particles in space. The term is applied to metal ions in a solid and to positive and negative ions in an ionic solid.

A

Lattice

19
Q

The forces of attraction which result from the electrostatic attraction between temporary dipoles and induced dipoles caused by movement of electrons in atoms and molecules.

A

London Dispersion Forces

20
Q

Fluids which mix with or dissolve in each other in all proportions

A

Miscible

21
Q

The regular recurrence of similar properties when the elements are arranged in order of increasing atomic number.

A

Periodicity

22
Q

A covalent bond between atoms of different electronegativity which results in an uneven distribution of electrons and a partial charge along the bond

A

Polar bond

23
Q

Shows the enthalpy of reactants and products and the enthalpy change during a chemical reaction

A

Thermal chemical equation

24
Q

Of a substance are their physical and chemical characteristics. These are often a reflection of the chemical Bonding and structure of the material.

A

Properties

25
Q

The resistance to flow that is exhibited by all liquids.

A

Viscosity