(4.9 x 10-2) (9.80 x 102)=

What is the energy of an electron in the third energy level of hydrogen?

Roman55 [17]

Answer:

Electrons in a hydrogen atom must be in one of the allowed energy levels. If an electron is in the first energy level, it must have exactly -13.6 eV of energy.

...

Energy Levels of Electrons.

Energy Level Energy

1 -13.6 eV

2 -3.4 eV

3 -1.51 eV

4 -.85 eV

4 0

3 years ago

Which is NOT a reason why we use the scientific method?

rusak2 [61]

Answer:

C. Because my teacher said so

Hope this helps :)

3 0

3 years ago

Read 2 more answers

Calculate the amount of heat needed to melt 91.5g of solid benzene ( C6H6 ) and bring it to a temperature of 60.6°C . Round your

Inessa [10]

Answer: The amount of heat required for melting of benzene is 20.38 kJ

Explanation:

The processes involved in the given problem are:

$1.)C_6H_6(s)(5.5^oC)\rightleftharpoons C_6H_6(l)(5.5^oC)\\2.)C_6H_6(l)(5.5^oC)\rightleftharpoons C_6H_6(l)(60.6^oC)$

For process 1:

To calculate the amount of heat required to melt the benzene at its melting point, we use the equation:

$q_1=m\times \Delta H_{fusion}$

where,

$q_1$ = amount of heat absorbed = ?

m = mass of benzene = 91.5 g

$\Delta H_{fusion}$ = enthalpy change for fusion = 127.40 J/g

Putting all the values in above equation, we get:

$q_1=91.5g\times 127.40J/g=11657.1J$

For process 2:

To calculate the amount of heat absorbed at different temperature, we use the equation:

$q_2=m\times C_{p}\times (T_{2}-T_{1})$

where,

$C_{p}$ = specific heat capacity of benzene = 1.73 J/g°C

m = mass of benzene = 91.5 g

$T_2$ = final temperature = 60.6°C

$T_1$ = initial temperature = 5.5°C

Putting values in above equation, we get:

$q_2=91.5\times 1.73J/g^oC\times (60.6-(5.5))^oC\\\\q_2=8722.05J$

Total heat absorbed = $q_1+q_2$

Total heat absorbed = $[11657.1+8722.05]J=20379.2=20.38kJ$

Hence, the amount of heat required for melting of benzene is 20.38 kJ

5 0

3 years ago

Determine how many grams of water are produced when burning 1.33 g of hexane, C6H14, as a component of gasoline in automobile en

miv72 [106K]

Combustion of hexane can be illustrated by the following reaction:
2C6H14 + 19O2 ...........> 12CO2 + 14H2O

From the periodic table:
mass of hydrogen = 1 gram
mass of oxygen = 16 grams
mass of carbon = 12 grams

Therefore:
molar mass of hexane = 6(12)+14(1) = 86 grams
mass of water = 2(1)+16 = 18 grams

From the balanced equation above:
2(86) = 172 grams of hexane produce 252 grams of water. To know the amount of water produced from 1.33 grams of hexane, all you have to do is cross multiplication as follows:
amount of water = (1.33x252) / 172 = 1.9486 grams

3 0

3 years ago

How many moles are there in 3.9 grams of potassium

polet [3.4K]

Answer:0.025576559594663 mole.

Explanation:

3 0

3 years ago