The 10% rule means that approximately there will be only 10% energy transferred from a trophic level into another. That was because the consumer on the upper level will use the energy before it was consumed. About 90% of the energy used so only 10% remain will be transferred.
Example: an antler eating grass with a total 100 calories. Then the antler is moving and growing, using 90 calories. Then a lion eats the antler, but the energy remains is only 10 calorie because 90 calories are already used.
Answer:
d) cut the large sized Cu solid into smaller sized pieces
Explanation:
The aim of the question is to select the right condition for that would increases the rate of the reaction.
a) use a large sized piece of the solid Cu
This option is wrong. Reducing the surface area decreases the reaction rate.
b) lower the initial temperature below 25 °C for the liquid reactant, HNO3
Hugher temperatures leads to faster reactions hence this option is wrong.
c) use a 0.5 M HNO3 instead of 2.0 M HNO3
Higher concentration leads to increased rate of reaction. Hence this option is wrong.
d) cut the large sized Cu solid into smaller sized pieces
This leads to an increased surface area of the reactants, which leads to an increased rate of the reaction. This is the correct option.
Ca₁₀(PO₄)₆(OH)₂ - hydroxyapatite
b. phosphorus (P) and calcium (Ca)
