A. Falling water turns a turbine that helps generate electricity
Answer:
The contributions are not listed in the question. I guess the following are the options you are talking about.
Same elements have same properties:
In 1803 Dalton gave the atomic theory that the properties of the atoms of the same element are same.
Electrons in Orbits:
Electrons were discovered in 1897 by J J. Thompson but the hypothesis of electrons in the orbits were given by Hantaro Nagaoka in 1904.
Plum pudding model:
Plum pudding model was given by J. J. Thompson in 1904 with the concept of positively charged medium containing the negatively charged electrons in it.
Positively Charged Atomic Nucleus:
Earnest Rutherford in 1911 discovered the positively charged atomic nucleus.
Answer:
The given molecules are SO2 and BrF5.
Explanation:
Consider the molecule SO2:
The central atom is S.
The number of domains on S in this molecule is three.
Domain geometry is trigonal planar.
But there is a lone pair on the central atom.
So, according to VSEPR theory,
the molecular geometry becomes bent or V-shape.
Hybridization on the central atom is
.
Consider the molecule BrF5:
The central atom is Br.
The number of domains on the central atom is six.
Domain geometry is octahedral.
But the central atom has a lone pair of electrons.
So, the molecular geometry becomes square pyramidal.
The hybridization of the central atom is 
.
The shapes of SO2 and BrF5 are shown below:
Answer is: 55.125 grams <span>of propane must be burned.
</span>Balanced chemical reaction: C₃H₈ + 5O₂ → 3CO₂ + 4H₂O.
Make proportion: 1 mol(C₃H₈) : 2220 kJ = n(C₃H₈) : 2775kJ.
n(C₃H₈) = 2775 kJ·mol ÷ 2220 kJ.
n(C₃H₈) = 1.25 mol.
m(C₃H₈) = n(C₃H₈) · M(C₃H₈).
m(C₃H₈) = 1.25 mol · 44.1 g/mol.
m(C₃H₈) = 55.125 g.
n - amount of substance.
