Chapter 7 Periodicity

Question 1

how are elements ordered in the periodic table

Answer 1

elements are ordered by increasing atomic number into groups and periods that are part of s,p,d,f blocks

Question 2

what is periodicity

Answer 2

Trends of periods and elements in periodic table

Question 3

what is ionisation energy

Answer 3

energy required to remove 1 mole of electrons from 1 mole of atoms to form 1 mole of 1+ ions in the gaseous state

Question 4

what is the ionisation energy formula

Answer 4

X(g) –> X+(g) + e-

Question 5

define first ionisation enthalpy

Answer 5

energy required to remove first outermost electron

Question 6

why must the element be in a gaseous state

Answer 6

so that no bonds or forces of attraction so get pure energy required

Question 7

what three factors do varying values depend on across a period

Answer 7

atomic radius
nuclear charge
electron shielding

Question 8

what is an allotrope

Answer 8

different forms of same element

Question 9

what bonds do the left hand side of the periodic table form

Answer 9

metallic

Question 10

what bonds do the mid table elements form (Si,C)

Answer 10

Giant covalent structures

Question 11

what bonds do the right hand side elements form

Answer 11

simple molecular covalent structures