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>
In your hand, the ball has higher potential energy than kinetic because it is still off of the ground but it isn't moving so there is no kinetic. As the ball rises, its potential and kinetic energy increases. At its peak, it has very high potential energy and very low kinetic energy. As it falls, the potential energy decreases but kinetic does not.
D = m/V
<span>V = m/d
V= 7.75 g / 1.71 g/cm^3
V= 4.53 c</span>m^3
I believe it’s D because phosphorus has the mass of 30.9.
This is a chemical reaction because a precipitate (solid) was formed from 2 liquids, and there was a color change as well
