All categories

3 years ago

Which of the following is the electron configuration of an excited atom that is likely to emit a quantum of energy?

Chemistry

1 answer:

Soloha48 [4]3 years ago

7 0

Answer: 1s2 2s2 2p6 3s1 3p1

Explanation:

Excitation of an electron is an elevation in energy level of the valence electron above the ground state electron.

When an electron gains energy, usually the outermost electron it moves from a orbital of lower energy to a orbital of higher energy, the element is in an excited state.

The electron configuration of ground state of magnesium is 1s2 2s2 2p6 3s1 3p2, when it gains energy the electronic configuration is 1s2 2s2 2p6 3s1 3p1 the excited state of Magnesium this is because the last electron moves from the 3S orbital to a higher energy orbital 3P

You might be interested in

Ethanol (C2H5OH) melts a - 144 oC and boils at 78 °C. The enthalpy of fusion of ethanol is 5.02 kj/mol, and its enthalpy of vapo

Romashka [77]

Answer:

For a: The total heat required is 36621.5 J

For b: The total heat required is 58944.5 J

Explanation:

For a:

To calculate the heat required at different temperature, we use the equation:

$q=mc\Delta T$ .........(1)

where,

q = heat absorbed

m = mass of substance

$c$ = specific heat capacity of substance

$\Delta T$ = change in temperature

To calculate the amount of heat required at same temperature, we use the equation:

$q=m\times \Delta H$ ........(2)

where,

q = heat absorbed

m = mass of substance

$\Delta H$ = enthalpy of the reaction

The processes involved in the given problem are:

$1.)C_2H_5OH(l)(35^oC)\rightarrow C_2H_5OH(l)(78^oC)\\2.)C_2H_5OH(l)(78^oC)\rightarrow C_2H_5OH(g)(78^oC)$

For process 1:

We are given:

Change in temperature remains the same.

$m=42.0g\\c_l=2.3J/g.K\\T_2=78^oC\\T_1=35^oC\\\Delta T=[T_2-T_1]=[78-35]^oC=43^oC=43K$

Putting values in equation 1, we get:

$q_1=42.0g\times 2.3J/g.K\times 43K\\\\q_1=4153.8J$

For process 2:

We are given:

Conversion factor: 1 kJ = 1000 J

Molar mass of ethanol = 46 g/mol

$m=42.0g\\\Delta H_{vap}=38.56kJ/mol=\frac{35.56kJ}{1mol}\times (\frac{1000J}{1kJ})\times (\frac{1}{46g/mol})=773.04J/g$

Putting values in equation 2, we get:

$q_2=42.0g\times 773.04J/g\\\\q_2=32467.7J$

Total heat required = $[q_1+q_2]$

Total heat required = $[4153.8J+32467.7J]=36621.5J$

Hence, the total heat required is 36621.5 J

For b:

The processes involved in the given problem are:

$1.)C_2H_5OH(s)(-155^oC)\rightarrow C_2H_5OH(s)(-144^oC)\\2.)C_2H_5OH(s)(-144^oC)\rightarrow C_2H_5OH(l)(-144^oC)\\3.)C_2H_5OH(l)(-144^oC)\rightarrow C_2H_5OH(l)(78^oC)\\4.)C_2H_5OH(l)(78^oC)\rightarrow C_2H_5OH(g)(78^oC)$

For process 1:

We are given:

Change in temperature remains the same.

$m=42.0g\\c_s=0.97J/g.K\\T_2=-144^oC\\T_1=-155^oC\\\Delta T=[T_2-T_1]=[-144-(-155)]^oC=11^oC=11K$

Putting values in equation 1, we get:

$q_1=42.0g\times 0.97J/g.K\times 11K\\\\q_1=448.14J$

For process 2:

We are given:

$m=42.0g\\\Delta H_{fusion}=5.02kJ/mol=\frac{5.02kJ}{1mol}\times (\frac{1000J}{1kJ})\times (\frac{1}{46g/mol})=109.13J/g$

Putting values in equation 2, we get:

$q_2=42.0g\times 109.13J/g\\\\q_2=4583.5J$

For process 3:

We are given:

Change in temperature remains the same.

$m=42.0g\\c_l=2.3J/g.K\\T_2=78^oC\\T_1=-144^oC\\\Delta T=[T_2-T_1]=[78-(-144)]^oC=222^oC=222K$

Putting values in equation 1, we get:

$q_3=42.0g\times 2.3J/g.K\times 222K\\\\q_3=21445.2J$

For process 4:

We are given:

$m=42.0g\\\Delta H_{vap}=38.56kJ/mol=\frac{38.56kJ}{1mol}\times (\frac{1000J}{1kJ})\times (\frac{1}{46g/mol})=773.04J/g$

Putting values in equation 2, we get:

$q_4=42.0g\times 773.04J/g\\\\q_4=32467.7J$

Total heat required = $[q_1+q_2+q_3+q_4]$

Total heat required = $[448.14+4583.5+21445.2+32467.7]J=58944.5J$

Hence, the total heat required is 58944.5 J

7 0

3 years ago

What energy is used when you ring a church bell?

nadezda [96]

Kinetic energy :) :)

3 0

3 years ago

What is the correct chemical name for the molecular compound if6?

Sati [7]

Iodine hexafluoride is the chemical name

5 0

3 years ago

What is the pH of a solution that contains 25 grams of hydrochloric acid (hcl) dissolved in 1.5 liters of water?

Darina [25.2K]

First we calculate the concentration of HCl:

Moles = mass / Mr
= 25 / 36.5
= 0.685 mol

Concentration = 0.685/1.5 = 0.457 mol / dm³

For a strong monoprotic acid, the concentration of hydrogen ions is equal to the acid concentration.

pH = -log[H+]
pH = -log(0.457)
= 0.34

4 0

3 years ago

Which statement does NOT apply to Alkenes?

nikdorinn [45]

Answer:

They are more stable than alkanes

Explanation:

Alkenes are a type of unsaturated hydrocarbons which means they have a double bond in their structure, or lack maximum number of hydrogen atoms on each carbon.
Alkenes have a general formula of CnH2n. They are called unsaturated hydrocarbons since they have a double bond. They are therefore less stable compared to alkanes and also are readily reactive.

6 0

4 years ago

Read 2 more answers