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3 years ago

What is the difference between a pure substance and an impure substance, on a molecular scale?

1 answer:

7 0

pure substance:
elements:
they are made by one kind of atoms,, have their own properties cannot be broken down into simpler substances,,
compounds:
made by chemical reactions of elements joined together,,they have different properties has compared to the elements which make them in compounds elements may be separated by chemical means..
impure substances :
they are made by physical combinations,,and they may be separate by physical means ,,mixture is the example ,, also their properties do not change after becoming a mixture,,

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dsp73

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4 years ago

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sasho [114]

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3 years ago

Calculate the energy, in joules, required to ionize a hydrogen atom when its electron is initially in the n =2 energy level. The

qaws [65]

Answer:

$E_{ionization}=5.45\times 10^{-19}\ J$

Explanation:

$E_n=-2.18\times 10^{-18}\times \frac{1}{n^2}\ Joules$

For transitions:

$Energy\ Difference,\ \Delta E= E_f-E_i =-2.18\times 10^{-18}(\frac{1}{n_f^2}-\frac{1}{n_i^2})\ J=2.18\times 10^{-18}(\frac{1}{n_i^2} - \dfrac{1}{n_f^2})\ J$

$\Delta E=2.18\times 10^{-18}(\frac{1}{n_i^2} - \dfrac{1}{n_f^2})\ J$

So, $n_i=2$ and $n_f=\infty$ (As the hydrogen has to ionize)

Thus,

$\Delta E=2.18\times 10^{-18}(\frac{1}{2^2} - \dfrac{1}{{\infty}^2})\ J$

$\Delta E=2.18\times 10^{-18}(\frac{1}{2^2})\ J$

$E_{ionization}=5.45\times 10^{-19}\ J$

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3 years ago

Where does the term carbohydrate come from? Explain by referring to the parts of this word

Troyanec [42]

A carbohydrate comes from a chain of carbon atoms with an H2O associated with each other

5 0

4 years ago

Why were colonists in new england angry at king james 2 abd governor edmund andros of new england?

Pani-rosa [81]

His strict imposition of autocratic rule was supported by his appointment by the King, who otherwise was not directly involved.

Explanation:

Andros’ imposition of Episcopalian worship in the Old South Meeting house, Boston his vigorous enforcement of the Navigation Acts.

He had earned the enmity of the local populace by enforcing the restrictive Navigation Acts.

He had infuriated Puritans in Boston by promoting the Church of England, which was rejected by many Nonconformist New England colonists.

When news of the overthrow of James II (1688) reached Boston, the colonists revolted, deposing Andros and imprisoning him.

His requirement that landholders take out new land patents and his limitations upon town meetings and rights of local taxation all aroused sharp resentment in colonial America.

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4 years ago