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2 years ago

A Se ion has a mass number of 79 and a charge of − 2 . Determine the number of neutrons, protons, and electrons in this ion.

Chemistry

1 answer:

posledela2 years ago

8 0

Answer:

45, 34, 36

Explanation:

The atomic number of Selenium is 34 and the atomic number is 79 also the atom has gained two electron denoted by superscript -2

number of neutrons = mass number - atomic number = 79 - 34 = 45

number of proton = atomic number = 34

number of electron = 34 + 2 = 36. In an atom the number of proton is always equal to number of electron if the atom is neutral but this Se atom has gain two so the number of electron will exceed the number of proton by 2.

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the pressure and temperature of 10 liters of gas are doubled. if the original condition are 2 atmosphere of pressure and 400k wh

Harman [31]

Answer:

$\boxed{\text{10 L}}$

Explanation:

We have two pressures, two temperatures, and one volume.

This looks like a question in which we can use the Combined Gas Law to calculate the volume.

$\dfrac{p_{1}V_{1}}{T_{1}} = \dfrac{p_{2}V_{2} }{T_{2}}$

Data:

$\begin{array}{rclrclrcl}p_{1}& =& \text{2 atm}\qquad & V_{1} &= & \text{10 L}\qquad & T_{2}& =& \text{400 K}\\p_{2}& =& \text{4 atm}\qquad & V_{2} &= & \text{?}\qquad & T_{2}& =& \text{800 K}\\\end{array}$

Calculation:

$\begin{array}{rcl}\dfrac{2 \times 10}{400}& =& \dfrac{4V_{2} }{800}\\\\0.050& = &0.0050V_{2}\\V_{2}& = &\mathbf{10 L}\end{array}\\\text{The final volume is }\boxed{\textbf{10 L}}$

4 0

2 years ago

Which type of bonding is most important in ch3ch2ch2ch2ch2ch3?

saveliy_v [14]

The compound $CH_3CH_2CH_2CH_2CH_2CH_3$ is formed only by sharing of electrons between the atoms. The structure of the compound is shown in the image.

Each line between two atoms represents the sharing of an electron pair which results in the formation of a single bond. Since, carbon has 4 electrons in its valence shell and hydrogen has 1 electron in its valence shell so in order to complete the octet ( to have 8 electrons in their valence shell, noble gas configuration) to attain stability carbon needs 4 more electrons and hydrogen needs 1 electron. So, sharing of electron will occur as shown in the image and the formed compound is stable in nature.

Since, the bond that is formed by sharing of electrons between atoms is known as covalent bond. So, covalent bonding is most important in $CH_3CH_2CH_2CH_2CH_2CH_3$ .

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3 years ago

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netineya [11]

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2 years ago

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crimeas [40]

The wood turns into ash and smoke so mass is nor destroyed or created.

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2 years ago

A potassium-40 sample starts with 50 atoms, and 1.25 billion years later, there are 25 atoms. What is the half-life of potassium

guapka [62]

D. 1.25 billion years

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