Answer:
Many plants have thorns on their stems or leaves. What is the MOST likely explanation for the evolution of thorns?
A) Thorns help plants produce more food from photosynthesis.
B) Thorns are an example of a mutation that arises in the genetic code of plants.
C) Thorns help plants to conserve resources like water and soil nutrients that may be used by other organisms.
D) Thorns are an adaptation that some plants have evolved in order to discourage herbivores from eating the plant.
2)
Explanation:
A diet rich in vegetables and fruits can lower blood pressure such as eating healthy
Given :
A compound has a molar mass of 129 g/mol .
Empirical formula of compound is C₂H₅N .
To Find :
The molecular formula of the compound.
Solution :
Empirical mass of compound :
Now, n-factor is :
Multiplying each atom in the formula by 3 , we get :
Molecular Formula, C₆H₁₅N₃
Answer:
Upwelling is the natural process which brings cold, nutrient-rich water to the surface. A huge upwelling regularly occurs off the coast of Peru, which enjoys a large fishing industry as a result. Upwelling is a process in which currents bring deep, cold water to the surface of the ocean.
Explanation:
good luck
Answer:
-125 kJ
Explanation:
You calculate the energy required to break all the bonds in the reactants. Then you subtract the energy to break all the bonds in the products.
H₂C=CH₂ + H₂ ⟶ H₃C-CH₃
Bonds: 4C-H + 1C=C 1H-H 6C-H + 1C-C
D/kJ·mol⁻¹: 413 612 436 413 347
The formula relating ΔHrxn and bond dissociation energies (D) is
ΔHrxn = Σ(Dreactants) – Σ(Dproducts)
(Note: This is an exception to the rule. All other thermochemical reactions are “products – reactants”. With bond energies, it’s “reactants – products”. The reason comes from the way we define bond energies.)
<em>For the reactant</em>s:
Σ(Dreactants) = 4 × 413 + 1 × 612 + 1 × 436 = 2700 kJ
<em>For the products:</em>
Σ(Dproducts) = 6 × 413 + 1 × 347 = 2825 kJ
<em>For the system</em>
:
ΔHrxn = 2700 - 2825 = -125 kJ
