Chapter 7 - Periodicity Flashcards Preview

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Flashcards in Chapter 7 - Periodicity Deck (20)
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1

What is periodicity?

is the trend in properties that shows a repeating pattern across different periods

2

How can elements be classified as s, p or d block?

according to which the sub-shell the outermost electrons are in

3

What is the nuclear charge?

no' of protons in the nucleus

4

What is shielding?

Number of completed electron shields between the nucleus and outer shell

5

What is the nuclear attraction?

The attraction between the nucleus + electrons in outer shells

6

What are the trends for the atomic radius across a period?

Atomic radius - DECREASES
Sheilding - SAME
Nuclear Charge - INCREASES
Nuclear Attraction - INCREASES

7

What are the trends for the atomic radius down a group?

Atomic radius - INCREASES
Sheilding - INCREASES
Nuclear Charge - INCREASES
Nuclear Attraction - DECREASING

(sheilding INCREASING leads to Nuclear attraction DECREASING

8

What are the trends for the ionisation energy across a period?

Atomic radius - DECREASES
Sheilding - SAME
Nuclear Charge - INCREASES
Nuclear Attraction - INCREASES

therefore ionisation energy INCREASES as it pulls electrons closer to nucleus

as you go across a period the force of attraction between the nucleus + outer electron increases (nuclear attraction). 1st IE INCREASES.

9

What are the trends for the ionisation energy down a period?

Atomic radius - INCREASES
Shielding - INCREASES
Nuclear Charge - INCREASES
Nuclear Attraction - DECREASES

(NA INCREASES bc Atomic radius + shielding outweighs increase in nuclear charge)

10

What is metallic bonding?

is the strong electrostaic attrcation between the cations and delocalised electrons

11

Describe the structure in solid metals?

-consists of positively charged metal ions (cations) held together by negatively charged outer shell electrons.

12

How do metals conduct electricity?

They conduct electricity due to the delocalised electrons that are mobile and so free to move anywhere in the solid metal structure.

13

Why do metals have high melting points?

Because of the strong electrostatic forces between the cations + electrons.
It requires a lot of energy to overcome this strong attractive force and move the ions from their position in the lattice.

14

Giant covalent lattices are 3-dimensional structures of atoms that are held by what force?

strong covalent bonds

15

In diamond what are the carbon atoms arranged in and with what bond angle?

TETRAHEDRAL
109.5
Each carbon atom is connected to 4 covalent bonds

16

Why do Giant covalent lattices have a high melting point?

Covalent bonds are strong. Large quantity of energy is needed to break the strong covalent bonds

17

Why do Giant covalent lattices do not conduct electricity?

In carbon + silicon all 4 outer shell is in covalent bonding so none available for conducting electricity.

18

Why are graphene and graphite exceptions to conduct electricity?

there is one electron available for conductivity

19

Why are Giant covalent lattices insoluble?

Covalent bonds holding together the atoms in lattice are far too strong to be broken by interaction with solvents

20

What is the 1IE?

Gh