3. Periodicity

Question 1

Effective nuclear charge

Answer 1

outer electrons increase with the group number of the element and across a period

Question 2

First Ionization energy

Answer 2

The energy required to remove one mole of electrons from 1 mole of gaseous atoms in their GROUND STATE

Question 3

Electron affinity

Answer 3

energy change that occurs when one mole of electrons is added to one mole of gaseous atom

Question 4

Electronegativity

Answer 4

Ability of an atom to attract electrons in a covalent bond

Question 5

coordinate bond

Answer 5

uses a lone pairof electron to form a covalent bond

Question 6

Ligand

Answer 6

is a species that uses a lone pair of electrons to form a coordinate bond with a metal ion.

Question 7

A chelate

Answer 7

is a complex containing at least 1 polydentate ligand.

Question 8

Nuclear charge trend

Answer 8

Increases down the group, Increases across a period

Question 9

Atomic radius trend

Answer 9

Increases- group;;
Decreases- period

Question 10

Ionic radius trend

Answer 10

Increases- group;;
Decreases- period

Question 11

Electron affinity trends

Answer 11

decreases- group;;
increases- period

Question 12

Ionization energy trends

Answer 12

decreases- group;;
increases- period

Question 13

most electronegative element

Answer 13

Fluorine

Question 14

M.P trends for group 1

Answer 14

decreases down the group

Question 15

M.P trends for group 7

Answer 15

increase down the group

Question 16

group 18 ft

Answer 16

colourless gasses, monoatomic, unreactive, stable octet

Question 17

Group 1 physical properties

Answer 17

good conductor, low density, shiny

Question 18

grp1 chem properties

Answer 18

very reactive, form ionic compounds with non-metals

Question 19

group1 reaction w water (hydrogen + metal hydroxide)
2K + 2H2O ->2KOH + H2

Answer 19

=Lithium- floats, reacts slowly, releases hydrogen but maintains its shape.
=Sodium- reacts vigorously, releases hydrogen, heat produced to melt unreacted metal.
=K- more vigorous, ignites hydrogen produced
<2k+2H2O=2K++2OH-+H2>

Question 20

grp 17 phy properties

Answer 20

coloured, gases - solids

Question 21

Grp 17 chem properties

Answer 21

very reactive (reactivity decreases down the group), form ionic compound w metals and covalent w non metals

Question 22

how does displacement reaction under grp 17 elements occur?

Answer 22

The more reactive halogen displaces the ions of the less reactive halogen from its compounds
2KBr +Cl2 = 2KCl+Br2

Question 23

Reaction w grp1 metals

Answer 23

halogens react w group 1 metals to form ionic halides
2Na + Cl2 = 2NaCl