Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Higher Chemistry 2016 > Unit 1 > Flashcards

Unit 1 Flashcards

1
Q

What is the definition of activation energy?

A

The energy required by colliding molecules to form an activated complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the definition of the bonding continuum?

A

A concept applied to bonding. Ionic and covalent bonding lie at opposite ends of the bonding continuum with polar covalent bonding in between.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the definition of collision geometry?

A

A term used to describe the way reactants collide with each other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the definition of collision theory?

A

A theory used to explain the factors which lead to a successful reaction. It explains how altering variables can affect the speed of reaction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What does collision theory require reactants to do?

A

Collide, have the correct collision geometry and have a minimum energy (the activation energy) before a reaction occurs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the definition of covalent atomic radius?

A

A measure of atomic size, being half the distance between the nuclei of two covalently-bonded atoms of an element. Covalent bond lengths between any two atoms can be obtained by adding the appropriate covalent atomic radii.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the definition of covalent bonding?

A

Bond formed between two atoms by the sharing of a pair of electrons. Usually occurs with non metal atoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the definition of a covalent network?

A

A very strong and stable structure formed by certain elements and certain compounds. All the atoms are held together by strong covalent bonds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are characteristics of covalent networks?

A

Covalent network compounds are all solids at room temperature and have very high melting points.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the definition of delocalised electrons?

A

Electrons which are not confined to a single orbital between a pair of atoms. Delocalised electrons are free to move away from the atom they came from.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the definition of an electron?

A

A particle that moves around the nucleus of an atom. It had a single negative charge but it’s mass is negligible compared with that of a proton or neutron.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the definition of electronegativity?

A

The strength of attraction by an atom of an element for its bonding electrons.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the definition of an endothermic reaction?

A

A reaction in which heat energy is absorbed from the surroundings. It has a positive enthalpy change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the definition of enthalpy change?

A

The difference in heat energy between reactants and products in a reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the definition it an exothermic reaction?

A

A reaction in which heat energy is released to the surroundings. It has a negative enthalpy change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the definition of group?

A

A column of elements in the Periodic Table

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the definition of intermolecular bonds?

A

Bonds between molecules.They are much weaker than intramolecular bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the definition of intramolecular bonds?

A

Bonds within molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the definition of a covalent bond?

A

Bond formed as a result of attraction between positive and negative ions

20
Q

What is the definition of ionisation?

A

The loss or gain of electrons by neutral atoms to form ions

21
Q

What is the definition of ions?

A

Atoms or groups of atoms that possess a positive e negative charge due to loss or gain of electrons

22
Q

What is the definition of a lattice?

A

The 3D arrangement of positive and negative ions in the solid, crystalline state of ionic compounds.

23
Q

What is the definition of London dispersion forces?

A

The weak forces of attractions between all atoms and molecules, caused by temporary dipoles

24
Q

What is the definition of metallic bonding?

A

The bonding responsible for typical metallic properties. Each atom loses its outer electrons to form positive ions

25
Q

How are ions packed in metallic bonding?

A

The ions pack together in a regular crystalline arrangement with the electrons delocalised through the structure, binding the ions together

26
Q

Name 3 examples of metallic properties?

A

Malleability, ductility and electrical conductivity in metals and alloys

27
Q

What is the definition of monatomic?

A

A term used to describe the noble gases since they are composed of individual atoms which do not bond to each other. They are held together by London dispersion forces in the liquid and solid state

28
Q

What is the definition of a non-polar covalent bond?

A

A covalent bond where both atoms share the electrons weakly

29
Q

Where does non-polar covalent bonding occur?

A

Between all elements that exist as molecules, since the atoms joining are identical. It also occurs in compounds where the bonding atoms have a small difference in electronegativity

30
Q

What is the definition of nucleus?

A

The extremely small centre of an atom

31
Q

What is found in the nucleus of an atom?

A

Neutrons and protons

32
Q

What is the definition of permanent dipole-permanent dipole interactions?

A

The attraction between molecules which possess a permanent dipole because of the presence of polar bonds

33
Q

What is the definition of polar covalent bonds?

A

Bonds formed between non-metallic atoms by sharing a pair of electrons. If the atoms have considerably different electronegativities, the electrons are not shared equally, the more electronegative atoms becoming slightly negative in comparison with the other atom. As a result it is non-polar

34
Q

What is the definition of an activated complex?

A

An unstable arrangement of atoms formed at the maximum of the potential energy barrier during a reaction

35
Q

What is temperature and what effect does temperature have on reaction rate?

A

Temperature is a measure of the average kinetic energy of the particles in a substance. If the temperature of a substance is increased more particles will have energies that are equal to or higher than the activation energy.

36
Q

If the total energy change for the bond breaking steps is less than for the bond making steps is the reaction exothermic or endothermic? Prove

A

The reaction will be exothermic as -

energy for bond breaking energy for bond making = ENDOTHERMIC

37
Q

In the first 20 elements of the periodic table, which are metallically bonded?

A

Lithium, beryllium, sodium, magnesium, aluminium, potassium, calcium

38
Q

In the first 20 elements of the periodic table, which are covalent networks?

A

Boron, carbon, sillicon

39
Q

In the first 20 elements of the periodic table, which are diatomic molecules?

A

Hydrogen, nitrogen, oxygen, fluorine,chlorine

40
Q

In the first 20 elements of the periodic table, which are monatomic elements?

A

Helium, neon, argon

41
Q

In the first 20 elements of the periodic table, which are covalent molecular solids?

A

Phosphorus, sulfur

42
Q

What is the definition of the first ionisation energy?

A

The first ionisation energy of an element is the energy required to remove one electron from the outer shell of each atom in one mole of gaseous atoms of the element

43
Q

What happens to the first ionisation energy on descending a group in the Periodic Table?

A

The first ionisation energy decreases

44
Q

What happens to the first ionisation energy from crossing a period on the periodic table left to right?

A

The first ionisation energy increases

45
Q

What is the definition of the second ionisation energy?

A

The energy required to remove one electron from one mole of one-positive gaseous ions

46
Q

What happens to the value of electronegativity on descending a group in the periodic table?

A

The electronegativity decreases

47
Q

When is a molecule described as polar?

A

If it has a permanent dipole

Higher Chemistry 2016 (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions