Natural selection cannot work if beneficial traits are not hereditary
Respuesta:
Yes.
Explicación:
Las teorías se pueden mejorar o modificar a medida que se recopila más información para que la precisión de la predicción sea mayor con el tiempo.
2.1618 grams of P4 is required to produce 4.21x10^22 molecules of phosphorus trifluoride.
Explanation:
The balanced chemical reaction for formation of PF3 from yellow phosphorus is given by:
P4 + 6F2 ⇒ 4PF3
1 mole of P4 reacts to give 4 moles of PF3
It is given that 4.21x10^22 molecules of PF3 are produced
so the number of moles can be calculated by the relation
number of molecules = number of moles × Avagadro number
number of moles = 
n = 
n= 0.06989 moles of PF3 is formed.
Applying stoichiometry,
1 mole of P4 gives 4 moles PF3
x mole will produce 0.06989 moles of PF3
= 
4x= 0.0698 × 1
x = 
x= 0.01745 moles of P4 will be required.
The weight of the phosphorus can be obtained by number of moles × atomic mass of one mole of P4
= 0.01745 × 123.89
= 2.1618 grams of P4.
A free-radical substitution reaction is likely to be responsible for the observations. The reaction mechanism of a reaction like this can be grouped into three phases:
- Initiation; the "light" on the mixture deliver sufficient amount of energy such that the halogen molecules undergo homologous fission. It typically takes ultraviolet radiation to initiate fissions of the bonds.
- Propagation; free radicals react with molecules to produce new free radicals and molecules.
- Termination; two free radicals combine and form covalent bonds to produce stable molecules. Note that it is possible for two carbon-containing free-radicals to combine, leading to the production of trace amounts of long carbon chains in the product.
Initiation

where the big black dot indicates unpaired electrons attached to the atom.
Propagation






Termination
