Fossil Fuels Account for Lowest Share of U.S. Energy Consumption in More than a Century. Fossil fuels supplied about 80 percent of the energy consumed in the United States in 2017, the lowest share since 1902, according to a new report from the U.S. Department of Energy.
Answer:
The correct answer is : 44 dollars.
Explanation:
A quarter is one fourth of a dollar that is the reason it is known as quarter. A quarter is 25 cents or 0.25 dollar in value. If Matthew has 176 quarters in his jar than the value of the total coins would be:
1 quarter = 0.25 dollar
1 quarter = 1/4 dollar.
4 quarter = 1 dollar
then, 176 / 4 = x dollar
= 44 dollar
Thus, The correct answer is : 44 dollars.
Answer:
The answer to your question is below
Explanation:
Propane = C₃H₈
Process
1.- Write the chemical reaction
C₃H₈ + O₂ ⇒ CO₂ + H₂O
balanced chemical reaction
C₃H₈ + 5O₂ ⇒ 3CO₂ + 4H₂O
Reactants Elements Products
3 C 3
8 H 8
10 O 10
b) Standard enthalpy
Propane -104.7 kJ/mol
Oxygen 0 kJ/mol
Carbon dioxide -393.5 kJ/mol
Water -241.8 kJ/mol
ΔH° = ∑ΔH° products - ∑H° reactants
ΔH° = 3(-393.5) + 4(-241.8) - [(-104.7) + 0]
-Simplification
ΔH° = -1180.5 kJ/mol - 967.2 kJ/mol + 104.7 kJ/mol
ΔH° = - 2042.5 kJ/mol
This reaction is exothermic because ΔH° is negative.
Answer: The volume of solution is 0.0459 L
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution

where,
n = moles of solute
= volume of solution in L
moles of HCl (solute) = 
Now put all the given values in the formula of molality, we get


Therefore, the volume of solution is 0.0459 L
Lets take one element from Group 6A, Let it be oxygen, The electronic configuration of Oxygen is as follow,
O = 8 = 1s², 2s², 2px², 2py¹, 2px¹
There are 6 electrons in the valence shell of elements present in Group 6A. The unpaired electrons in 2px and 2py are involved in forming covalent bond, while the pair of electrons in 2s and 2px are unshared and act as lone pair of electrons.
Result:
There are TWO unpaired electrons present in the ground state of Group 6A elements.