Question

No 7 pleaaseeee......

Answer 1

Isotop 1 --> a1 = x%
isotop 2 --> a2 = (100-x)%
Ar = m1 . a1 + m2 . a2 / 100%
43,7 = 42 x %+ 44 (100-x)%/ 100%
4370 = 42x + 4400 - 44x
2x = 30
x = 15%

a1 = 15%
a2 = (100%-15%) = 85%

So perbandingannya 15 : 85

Semoga Membantu

Answer 2

Misal persen isotop X-42 = a%
misal persen isotop x-44  = b% = 100% - a%

massa atom relatif X = 43,7

rumusnya :

massa atom relatif X = a% . massa 1 atom isotop X-42 + b% .massa 1 atom isotop X-44

massa atom relatif X = a% . massa 1 atom isotop X-42 + (100%-a%) .massa 1 atom isotop X-44

massa atom relatif X = (a/100). 42 + ((100-a)/100) . 44

massa atom relatif X = (0,01 a). 42 + (1-0,01 a). 44

43,7 = 0,42 a + 44 - 0,44a

43,7 - 44 = 0,42 a- 0,44a
- 0,3 = - 0,02 a

maka a = 0,3 / 0,02 = 30/2 = 15

karena a = 15 maka  %a = 15 %
maka:
% b = 100% - %a
%b = 100% - 15 % = 85 %

maka :
%isotop X-42 : %isotop X-44 = 15% : 85 % 

%isotop X-42 : %isotop X-44 = 15 : 85 = 3 : 17