Similar organisms that are not related are an example of A.  Natural selection
 B. Convergent evolution 
 C. Divergent evolution 
 D. Common ancestor

I think it is because it is directly about the north or south pole (I forget) so while all the other stars seem to rotate around because the Earth is rotating but the North Star is directly in the center. Don't take my word though.

Answer:

Iron can not form iron(i) selenide however it can form iron(ii) selenide.

Explanation:

The possible oxidation states of iron are +2 and +3.

Iron can form iron (ii) selenide.

The formula of iron (ii) selenide is FeSe.

In iron (ii) selenide the oxidation state of iron is +2.

The ratio of both atoms are 1:1.

Its molecular weight is 134.82 g/mol.

It is toxic compound.

Its melting point is 965°C.

Its density is 4.72 g/cm³.

Iron can also form iron (iii) selenide.

The formula of iron (iii) selenide is Fe₂Se₃.

In  iron (iii) selenide the oxidation state of iron is +3.

The ration of both atoms are 2:3.

It also known as ferric selenide.

Its molecular weight is 348.57 g/mol.

Answer: 250 kJ

Explanation: According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.

According to Hess’s law, the chemical equation can be treated as algebraic expressions and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.

  (1)

  (2)

Net chemical equation:

  (3)

Adding 1 and 2 we get,

  (4)

Now dividing equation (4) by 4, we get

  (4)

Answer:

Answer is B Pampas

Explanation:

Edge2020

Answer:

n CO2 = 20 mol

Explanation:

balanced reaction:

• 2C5H14 + 17O2 → 10CO2 + 14H2O

∴ n C5H14 = 4 mol

⇒ mol CO2 = ( 4 mol C5H14)*(10 mol CO2/2 mol C5H14)

⇒ mol CO2 = 20 mol