One difference is that some animals are polyp and some are medusa.
The other difference is that some animals have medusa in their life or polp in their life cycle.
Hope these two differences helps :D
Answer:
Option D is good to go!
Explanation: as per the reactivity series more reactive substances will react with the counterpart substance.The most reactive substance here is calcium while the least reactive is aluminium, the magnesium comes in between.As per their reactivity, these substances will react with oxygen.
Explanation:
Answer:reaction 2,5,6
Explanation:
First, we need to define what the enthalpy of formation is and what the enthalpy of reaction is____
<u>Formation Enthalpy</u>: It is the variation of the calorific energy in the reaction of ONE MOL of a compound starting from the elements.
<u>Reaction Enthalpy: </u>It s the variation of the calorific energy in the reaction of reactives, in this cases could be any quantity of mol
Then: We have six reactions:
1)CaCO3(g)→ CaO+ CO2(g)
2)Li(s)+12F2(g)→LiF(s)
3)CO(g)+12 O2(g)→ CO2(g)
4)2Li(s)+F2(g)→2LiF(s)
5)Li(s)+12F2(l)→LiF(s)
6)C(s,graphite)+ O2(g)→ CO2(g)
The enthalpy of reaction will be equal to reaction enthalpy when we produce one mol from elements
The answer is the reactions 2,5,6
Half life is the time taken by a radioactive isotope to decay by half its original mass. In this case, the halflife of the radioactive isotope is 5000 years.
Initially the mass is 100 %; thus the mass that will be left will be given by;
New mass = Original mass × (1/2)^n where n is the number of half lives;
n = 10000/5000 = 2
New mass = 100% ×(1/2)^2
= 100 % × 1/4
= 25%
Therefore; the mass left after 10000 years is 25% or 1/4 of the original mass.