Atomic mass of Br = 79.904
<span>Now lets say y% is abundance of 79Br. </span>
<span>Then abundance of 81Br = (100 - y) </span>
<span>mass due to 79Br = 78.9183 * y/100 = 0.789183y
</span><span>mass due to 81Br = 80.9163 x (100 - y)/100 = 0.809163(100 - y) </span>
<span>Therfore</span>
<span>0.789183y+ 0.809163(100 - y) = 79.904 </span>
<span>0.789183y + 80.9163 - 0.809163y = 79.904 </span>
<span> - 0.01998y= 79.904 - 80.9163
= - 1.0123 </span>
<span>y = 1.0123/0.01998 = 50.67% </span>
<span> 79Br = 50.67% </span>
<span>now
81Br = 100 - 50.67 = 49.33%
hope this helps</span>
Answer:
Distance in kilometre = 4.242 x 10¹² km
Explanation:
Given:
Distance of Proxima Centauri = 4.242 light years
Find:
Distance in kilometre
Computation:
1 light year = 10,000,000,000,000 km
So,
4.242 light years = 4.242 x 10,000,000,000,000
Distance in kilometre = 4.242 x 10¹² km
