CLASSIFICATION OF ELEMENTS

Question 1

who created the first periodic table

Answer 1

johan doberneir

Question 2

what was the first periodic table and by whom

Answer 2

triads and johan doberneir

Question 3

specialty of triads

Answer 3

properties of middle elements are middle of the properties

Question 4

what did AEB Chancourtis make

Answer 4

cylindrical table

Question 5

what john alexander newlands make

Answer 5

law of octaves.. every eighth element and similar properties was awarded devy medal

Question 6

what was disadvantage of john alexanders table

Answer 6

lasted only upto the first twenty elements

Question 7

what did lothar meyer do

Answer 7

he plotted physical properties to atomic weight and found periodic pattern

Question 8

what is mendeleev law

Answer 8

periodicity is function of atomic weight

Question 9

demerits of mendeleev table

Answer 9

misplaced some elements(iodine is lighter than telleurium but was placed after it), isotopes no space,

Question 10

waht is eka silicon and eka aluminum

Answer 10

germanium and gallium

Question 11

henry mosleyes graph

Answer 11

root of frequency and atomic number

Question 12

modern periodic law

Answer 12

the elements are periodic functions of their atomic number

Question 13

mendeleev series are called —– in modern rable

Answer 13

periods

Question 14

IUPAC Nomenclature of nine

Answer 14

enn

Question 15

3d series starts with

Answer 15

Sc

Question 16

4d series starts with atomic no

Answer 16

39 yt

Question 17

in s block which are not predominantly ionic

Answer 17

Li and Be

Question 18

Rreactivity and metallic character increases as we go down the group T/F

Answer 18

True

Question 19

what are representitive elements

Answer 19

s and p block elemetns

Question 20

chalcogens and halogens group nos

Answer 20

16 and 17

Question 21

non metallic character increases

Answer 21

by moving from left to right

Question 22

which element shows s0 configuration

Answer 22

Pd (4d105s0)

Question 23

what are Transuranium elements

Answer 23

elements after uranium

Question 24

zn,hg,cd do not show most of the transition element properties t/f

Answer 24

true

Question 25

exceptions for melting points

Answer 25

carbon and boron

Question 26

which are the semi metals

Answer 26

Ge,Ar,Si,Sb,Te

Question 27

reactivity along series

Answer 27

high reactivity to low to maximum

Question 28

expalin size of atom through series and group

Answer 28

size decreases because nuclear charge increase and en in same shell itself and increases down the group because shell number increases and the inner en shield the valence electrons

Question 29

what is ionisation enthalpy

Answer 29

energy required to remove an en from the gaseous atom iground state

Question 30

trends of ionisation enthalpy

Answer 30

increase across series and decreases down the group

Question 31

shielding is effectice whe inner en are filled t/f

Answer 31

true

Question 32

which orbital has the most attraction

Answer 32

s orbital

Question 33

which has higher ionisation enthalpy Be orB

Answer 33

Be because p en is easier to remove due to shielding effect

Question 34

explain en gain enthalpy

Answer 34

measure of which element likes to be anion

Question 35

en gain enthalpy trends

Answer 35

increase across a period(-ve), smaller size and more nuclear attraction decreases down the group because en is far from nucleus

Question 36

exception of en gain enthalpy

Answer 36

O and F because n=2 and repulsion from other electrons

Question 37

different electronegativity scales

Answer 37

linus paulling,mulikan,allred rochow scale

Question 38

electronegativity trends

Answer 38

increases across a period and decreases down the group

Question 39

diagonal relationships

Answer 39

Li and Mg, Be and Al

Question 40

reason for diagonal relationship

Answer 40

high EN, large charge to size ratio, small size

Question 41

oxides in left side form basic oxide and right side forms acidic oxide T/F

Answer 41

True

Question 42

which is the most basic oxide and acidic oxide

Answer 42

Na2O and Cl2O7

Question 43

neutral oxides

Answer 43

CO,NO,N2O