<span>C7H8
First, determine the number of relative moles of each element we have and the molar masses of the products.
atomic mass of carbon = 12.0107
atomic mass of hydrogen = 1.00794
atomic mass of oxygen = 15.999
Molar mass of CO2 = 12.0107 + 2 * 15.999 = 44.0087
Molar mass of H2O = 2 * 1.00794 + 15.999 = 18.01488
We have 5.27 mg of CO2, so
5.27 / 44.0087 = 0.119749 milli moles of CO2
And we have 1.23 mg of H2O, so
1.23 / 18.01488 = 0.068277 milli moles of H2O
Since there's 1 carbon atom per CO2 molecule, we have
0.119749 milli moles of carbon.
Since there's 2 hydrogen atoms per H2O molecules, we have
2 * 0.068277 = 0.136554 milli moles of hydrogen atoms.
Now we need to find a simple integer ratio that's close to
0.119749 / 0.136554 = 0.876937
Looking at all fractions n/m where n ranges from 1 to 10 and m ranges from 1 to 10, I find a closest match at 7/8 = 0.875 with an error of only 0.001937, the next closest match has an error over 6 times larger. So let's go with the 7/8 ratio.
The numerator in the ratio was for carbon atoms, and the denominator was for hydrogen. So the empirical formula for toluene is C7H8.</span>
Answer: Option (a) is the correct answer.
Explanation:
Atomic number is the sum of only total number of protons present in an element. Whereas mass number is the sum of total number of both protons and neutrons present in an element.
For example, given atom has mass number as 15 and its atomic number is 7.
Therefore, number of neutrons present in it will be calculated as follows.
Mass number = no. of protons + no. of neutrons
15 = 7 + no. of neutrons
no. of neutrons = 15 - 7
= 8
Thus, we can conclude that the given atom contains 8 neutrons in the nucleus.
Answer:
Desert
Explanation:
The adaptation shown by the given plants and animals shows that they will adapted to the desert biome.
It is so because, due to high temperature of desert some desert animals like camel have the storage of fat in humps or tails; some animals have large ears such as Jackrabbits, it helps to release body heat and adapt in high temperature; plants have thick water holding tissues to reduce water loss in heat and waxy coating that keeps the plants cooler and reduce moisture loss.
Hence, the correct answer is "Desert".
The given question is incomplete. The complete question is:
How much heat is produced when 24.8 g of 
is burned in excess oxygen gas
Given: 
ΔH= −802 kJ.
Answer: 1243.1 kJ
Explanation:
Heat of combustion is the amount of heat released on complete combustion of 1 mole of substance.
Given :
Amount of heat released on combustion of 1 mole of methane = 802 kJ kJ/mol
According to avogadro's law, 1 mole of every substance occupies 22.4 L at NTP, weighs equal to the molecular mass and contains avogadro's number 
of particles.
1 mole of weighs = 16 g
Thus we can say:
16 g of on combustion releases heat = 802 kJ
Thus 24.8 g of on combustion releases =
Thus heat released when 24.8 g of methane is burned in excess oxygen gas is 1243.1 kJ
There are 9 orbitals in the third energy level and 25 orbitals in the fifth energy level.
I hope this helps you.
