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3 years ago

What group of elements generally have the lowest second ionization energy?

2 answers:

7 0

Hey there,
The ionization energy decreases from top to bottom in groups, and increases from left to right across a period.
Helium has the largest first ionization energy, while francium has one of the lowest.

Hope this helps :))

~Top

ICE Princess25 [194]3 years ago

4 0

By definition, the first ionization energy is the energy required to remove the most loosely held electron from one mole of gaseous atoms to produce 1 mole of gaseous ions each with a charge of 1+.

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Many substances can go through physical and chemical changes. Which of the following is an example of a physical change? Questio

Ann [662]

Mixing baking soda with vinegar to form CO2

(Isn't the one used to make volcano models)

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3 years ago

The skeletal structure in line‑angle (line‑bond) mode of 2‑isopropyltoluene is shown. Identify the number of hydrogen atoms boun

Shalnov [3]

Answer:

Fourteen hydrogen atoms are bounded in total to the carbon atoms in the structure

Explanation:

The boxes that show "one" indicate that there is only one hydrogen atom bonded to that particular carbon atom while those that show "zero" shows there are no hydrogen atoms bonded to that particular carbon atom. Those that show "three" indicate that there are three hydrogen atoms bonded to that particular carbon.

There are 10 carbon atoms in the structure.

NOTE that each of these carbon atoms must be surrounded with four bonds; which was how the number of hydrogen atoms (numbers in the boxes) weree determined.

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3 years ago

Which of the following pure compounds will exhibit hydrogen bonding?

zimovet [89]

Explanation:

For a compound to show hydrogen bonding it is necessary that the hydrogen atom of the compound should be attached to more electronegative atom like fluorine, oxygen or nitrogen.

For example, $CH_{3}CH_{2}OH$ , $CH_{3}NH_{2}$ and $NH_{3}$ all these compounds contain an electronegative atom attached to hydrogen atom.

Therefore, these pure compounds will exhibit hydrogen bonding.

Thus, we can conclude that out of the given options $CH_{3}CH_{2}OH$ , $CH_{3}NH_{2}$ and $NH_{3}$ are the pure compounds which will exhibit hydrogen bonding.

4 0

3 years ago

Be sure to answer all parts. What is the [H3O+] and the pH of a buffer that consists of 0.26 M HNO2 and 0.89 M KNO2? (K, of HNO2

Aleksandr-060686 [28]

Answer : The $H_3O^+$ ion concentration is, $1.12\times 10^{-3}M$ and the pH of a buffer is, 2.95

Explanation : Given,

$K_a=7.1\times 10^{-4}$

Concentration of $HNO_2$ (weak acid)= 0.26 M

Concentration of $KNO_2$ (conjugate base or salt)= 0.89 M

First we have to calculate the value of $pK_a$ .

The expression used for the calculation of $pK_a$ is,

$pK_a=-\log (K_a)$

Now put the value of $K_a$ in this expression, we get:

$pK_a=-\log (7.1\times 10^{-4})$

$pK_a=4-\log (7.1)$

$pK_a=3.15$

Now we have to calculate the pH of the solution.

Using Henderson Hesselbach equation :

$pH=pK_a+\log \frac{[Salt]}{[Acid]}$

$pH=pK_a+\log \frac{[KNO_2]}{[HNO_2]}$

Now put all the given values in this expression, we get:

$pH=3.15+\log (\frac{0.89}{0.26})$

$pH=2.95$

The pH of a buffer is, 2.95

Now we have to calculate the $H_3O^+$ ion concentration.

$pH=-\log [H_3O^+]$

$2.95=-\log [H_3O^+]$

$[H_3O^+]=1.12\times 10^{-3}M$

The $H_3O^+$ ion concentration is, $1.12\times 10^{-3}M$

4 0

3 years ago

HURRY !!!!!! How did kelper describe the planets Orbits ?

Andrei [34K]

Kepler's Laws of Planetary Motion. While Copernicus rightly observed that the planets revolve around the Sun, it was Kepler who correctly defined their orbits.

Sorry about the holds, copied it from google...

8 0

3 years ago