Ultraviolent radiation i believe
Answer:
<em>The correct option is b. new species make the environment less suitable for previous ones.</em>
Explanation:
In ecology, succession can be described as the changes in a species structure over a period of time. In a community, newer species tend to have better characteristics and adaptations to survive in a community as compared to the older ones. As a result, the new species begin to take over the land and the older ones gets removed. It is due to ecological succession that climax communities are formed from pioneer species.
The various planets are thought to have formed from the solar nebula, the disc-shaped cloud of gas and dust left over from the Sun's formation. The currently accepted method by which the planets formed is accretion, in which the planets began as dust grains in orbit around the central protostar.
Number of moles CuCl₂ :
mass solute / molar mass
31.0 / 134.4520 => 0.230 moles of CuCl₂
Mole ratio :
CuCl₂ + 2 NaNO₃ = 2 NaCl + Cu(NO₃)₂<span>
</span>
1 mole CuCl₂ -------- 2 moles NaCl
<span> 0.230 moles -------- ? moles NaCl
</span>
moles NaCl = 0.230 x 2 / 1
moles NaCl = 0.46 / 1
= 0.46 moles of NaCl ( molar mass 58.44 g/mol )
Mass of NaCl:
1 mole ---------- 58.44 g
0.46 moles ----- ( mass of NaCl in theory )
mass of NaCl = 0.46 x 58.44 / 1
mass of NaCl = 26.8824 / 1
= 26.8824 g of NaCl
<span>yield of NaCl :
</span>
NaCl produce / NaCl in theory x 100 %
( 21.2 / 26.8824 ) x 100
( 0.788 ) x 100 => 78.8 %
hope this helps!
