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3 years ago

Why do historians analyze historical events and cause and effect relationship

2 answers:

8 0

Recognizing patterns of cause and effect is an important analytical skill that allows historians to explain why things happened the way they did in the past. It's also a strategy that can make it possible to predict what may happen in the future.

Arte-miy333 [17]3 years ago

7 0

Answer:

yeah. def

Explanation:

becuase someone told me to

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When computing using dimensional analysis:

shusha [124]

Answer: unit conversions can be done either simultaneously or separately

Explanation:

6 0

3 years ago

A metal ion (X) with a charge of 4+ is attracted to non metal ion (Z) with a charge of 3-. Which of these formulas represents th

Brums [2.3K]

Answer:

Explanation:

the charges need to balence out

so finding the LCM which is 12 we find we need 3x's

and 4 zs

so that makes the formula X3Z4 which is D

6 0

2 years ago

Solid NaI is slowly added to a solution that is 0.0079 M Cu+ and 0.0087 M Ag+.Which compound will begin to precipitate first?NaI

NeTakaya

Answer :

AgI should precipitate first.

The concentration of $Ag^+$ when CuI just begins to precipitate is, $6.64\times 10^{-7}M$

Percent of $Ag^+$ remains is, 0.0076 %

Explanation :

$K_{sp}$ for CuI is $1\times 10^{-12}$

$K_{sp}$ for AgI is $8.3\times 10^{-17}$

As we know that these two salts would both dissociate in the same way. So, we can say that as the Ksp value of AgI has a smaller than CuI then AgI should precipitate first.

Now we have to calculate the concentration of iodide ion.

The solubility equilibrium reaction will be:

$CuI\rightleftharpoons Cu^++I^-$

The expression for solubility constant for this reaction will be,

$K_{sp}=[Cu^+][I^-]$

$1\times 10^{-12}=0.0079\times [I^-]$

$[I^-]=1.25\times 10^{-10}M$

Now we have to calculate the concentration of silver ion.

The solubility equilibrium reaction will be:

$AgI\rightleftharpoons Ag^++I^-$

The expression for solubility constant for this reaction will be,

$K_{sp}=[Ag^+][I^-]$

$8.3\times 10^{-17}=[Ag^+]\times 1.25\times 10^{-10}M$

$[Ag^+]=6.64\times 10^{-7}M$

Now we have to calculate the percent of $Ag^+$ remains in solution at this point.

Percent of $Ag^+$ remains = $\frac{6.64\times 10^{-7}}{0.0087}\times 100$

Percent of $Ag^+$ remains = 0.0076 %

8 0

3 years ago

In this experiment, you were asked to calculate your percent yield of alum assuming that you started with pure aluminum. Actuall

neonofarm [45]

Answer:

Percent yield of alum is 38.6%

Explanation:

Find attached calculations for detailed explanation.

3 0

3 years ago

58. Explain why each successive ionization of an electron

ale4655 [162]

Answer:

It's because removal of electron from an atom, reduces the size of an atom.

Explanation:

When an electron is removed from an atom, it becomes an ion and in this case it will become a postive ion.

When an electron is removed from an atom, the charge balance of an atom is disturbed and positive charge increases in comparison to the negative charge. This results in increase nuclear (positive) charge which exerts greater attraction on the remaining electrons and as a result the remaining electrons are more strongly attracted by the nucleus and in this way the atomic size is decreased. Due to this increased nuclear attraction and reduced atomic size, it bcomes difficult to remove more electeon from the positively charged ion of reduced size. This is the reason that each successive ionization of electron requires a greater amount of energy.

The ionization energy has inverse relation with the size or radius of an atom. This also justifies the reason that why each successive ionization of an electron requires greater amount of energy.

6 0

3 years ago