2. Trends in periodic table Flashcards Preview

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Flashcards in 2. Trends in periodic table Deck (15)
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1
Q

What is covalent radius?

A

Half the distance between bonding nuclei

2
Q

Why is there no covalent radii for the Noble Gases?

A

They do not form covalent bonds.

3
Q

What is the trend for covalent radius across a period?

A

Decreases due to greater pull of extra protons on shells

4
Q

What is the trend for covalent radius down a group?

A

Increases due to greater number of electron shells (levels)

5
Q

What is 1st Ionisation energy?

A

The energy required to remove 1 mole of electrons from 1 mole of atoms in the gaseous state

6
Q

What is the trend for ionisation energy across a period?

A

Increases due to greater pull of extra protons on outer electrons

7
Q

What is the trend for ionisation energy going down a group?

A

Decreases due to greater shielding effect of extra shells and greater distance of outer electrons from nucleus

8
Q

Why is 2nd ionisation energy always greater than the 1st?

A

It takes more energy to remove an electron from a positively charged ion

9
Q

Why is the 2nd ionisation energy of group 1 metals so much higher than the 1st?

or

Why is the 3rd ionisation energy of group 2 metals so much higher than the 2nd?

or

Why is the 4rd ionisation energy of group 3 metals so much higher than the 3rd?

A
  • electron is being removed from a stable (full) shell or electron arrangement
  • this shell has less shielding effect from the nucleus
  • this shell lies closer to the nucleus
10
Q

What is electronegativity?

A

The attraction an atom’s nucleus has for bonding electrons

11
Q

What is the trend fo electronegativity down a group

A

Decreases due to greater shielding effect of extra shells and greater distance of bonding electrons from nucleus

12
Q

What is the trend for electronegativity across a period

A

Increases due to greater pull of extra protons on shared pair of electrons

13
Q

Ionic radius going down a group

A

Increases due to extra electron shells being added as you go down group

14
Q

How do the ionic radii of metals compare to corresponding covalent radii?

A

Ionic radii are smaller due to outer electrons being lost leading to 1 shell fewer

15
Q

How do the ionic radii of non-metals compare to corresponding covalent radii

A

Ionic radii are greater due to extra electrons on outer shell causing greater repulsion between shells.