Module 2: Chapter 5 (Electrons and Bonding) Flashcards Preview

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Flashcards in Module 2: Chapter 5 (Electrons and Bonding) Deck (23)
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1

How many electrons can fit in the first four main shells?

1 = 2
2 = 8
3 = 18
4 = 32

2

Name the sub-shells in the first four shells

1 = 1s -> 2e-

2 = 2s -> 2e-
2p -> 6e-

3 = 3s -> 2e-
3p -> 6e-
3d -> 10e-

4 = 4s -> 2e-
4p -> 6e-
4d -> 10e-
4f -> 14 e-

3

What is a 'main shell' also referred to as?

principal quantum number, n

4

What is the electronic configuration order of subshells?

In order of increasing energy...

1s2s2p3s3p4s3d4p

5

How is a shorthand version of configuration made?

Giving the previous noble gas in the periodic table, plus the remaining outer shell electrons

6

How is electron configuration constructed for ions?

'last in-first out'
exception of 4s, so 4s empties before 3d, as it has a slightly lower energy level

7

What are the different blocks of the periodic table?

- Hydrogen and Groups 1+2 are s-block
- Transition metals are d-block
- Groups 3-8(0) are p-block
- Extra are f-block

8

What is an atomic orbital?

An orbital describes the region of space where there is a high probability of finding an electron

9

How many electrons are in each orbital?

each orbital can only hold 2 electrons

10

How do electrons behave in orbitals?

Electrons in the same orbital have to have opposite spins
- as far as possible electrons in the same sub-shell prefer to be in separate orbitals to minimize repulsion

11

Describe a s-orbital

- electron cloud is within the shape of a sphere
- the greater the shell number n, the greater the number of its s-orbital

12

Describe a p-orbital

- electron cloud is within the shape of a dumb-bell
- the three separate p-orbitals are at right angles to each other
- the greater the shell number n, the further the p-orbital from the nucleus

13

What is an ionic bond?

the electrostatic attraction between positively and negatively charged ions

14

What do dot and cross diagrams show?

used to distinguish where the electrons originally came from

15

Describe the structure of ionic compounds

- in the compound every ion attracts oppositely charged ions in all directions
- the result is a giant ionic lattice

16

What are the properties of ionic compounds?

- in general the physical properties of a substance are always explained by consideration of structure and bonding
- generally most compounds have a high mp/bp (solid at room temp)
- due to the very strong electrostatic attraction between oppositely charged ions, lots of energy is needed to break the lattice

17

Describe the electrical conductivity of ionic compounds

- solid ionic compound will no conduct electricity as the ions can't move and carry charge, in fixed positions in the lattice
- only carry charge unless molten or dissolved

18

Describe solubility of ionic compounds

- often *not always* soluble in water, tend to be insoluble in most other solvents
- water is polar
- in a solution an ion can attract many water molecules
- the compound will tend to be soluble if the attractions formed compensate for those broken down when the lattice breaks down
- it is a fine balance, making predictions about solubility difficult

19

What is a covalent bond?

covalent bonding is electrostatic attraction between shared pair of electrons and the nuclei of the two bonded atoms

20

Describe a covalent bond

- a covalent bond is formed by the overlap of atomic orbitals
- in a covalent bond the attraction is localised, this is in contrast to ions which can attract in all directions

21

How many bonds does carbon, hydrogen, nitrogen and oxygen form?

4, 1, 3, 2

22

How many orbitals does each subshell have?

- an s subshell has 1 orbital
- p has 3 orbitals
- d has 5 orbitals
- f has 7 orbitals

23

What is a dative covalent bond?

A dative covalent bond is a shared pair of
electrons where both electrons are from the
same atom.