Answer: The empirical formula is
.
Explanation:
Mass of C = 1.71 g
Mass of H = 0.287 g
Step 1 : convert given masses into moles.
Moles of C = 
Moles of H = 
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For C =
For H =
The ratio of C: H = 1: 2
Hence the empirical formula is
.
Answer:

Explanation:
Given:
For a school event, 1/6 of the athletic field is reserved for the fifth -grade classes and the reserved part of the field is divided equally among the 4 fifth grade classes in the school.
To find: fraction of the whole athletic field reserved for each fifth class
Solution:
Fraction of the whole athletic field reserved for four fifth classes = 
So, fraction of the whole athletic field reserved for each fifth class = 
I think the correct answer would be the third option. The correct name for the hydrocarbon described above would be 2-heptyne. It has a chemical formula written as CH3 - CH2 - CH2 - CH2 - C ≡ C - CH3. Counting the number of carbons, we have 7 carbon atoms so we use the prefix hepta-. Since it has a triple bond then it is an alkyne. So, it would be named as heptyne. The triple bond is located on the second carbon atom so we write 2 before the name to indicate the location of the triple bond. The name of the compound would be 2-heptyne.
<span>In a popular classroom demonstration, solid sodium is added to liquid water and reacts to produce hydrogen gas and aqueous sodium hydroxide. Balanced chemical equation for this reaction is given below.
Na-sodium , H2o- water, H-hydrogen gas and NaOH- aqueous sodium hydroxide.
Two atoms of Na react with two atoms of water and this reaction will give us H (hydrogen gas) and two atoms of NaOH (aqueous sodium hydroxide).
2Na + 2 H2o = H2 +2NaOH.</span>
Mezoic era began 252m years ago and ended 6.6m years ago.
It was a time of geological and biological transition. During this era the continents began to drift to their present configuration.
3 of the largest mass extinction occurred at this era. One which include the dinosaurs.
I hope this helped. :)