Answer: Option (D) is the correct answer.
Explanation:
- A pure substance is defined as the substance that is made up of only one type of atom or only one type of molecule.
For example, is a molecule and it is a pure substance.
Also, substances that contain two or more different element which are chemically combined in a fixed ratio by mass are known as compounds. They are also pure substances.
A pure substance can only be separated by a chemical method and not by any physical method.
- A heterogeneous mixture is defined as the mixture which contains non-uniform composition of solute particles into the solution.
For example, mud dissolved in water.
It is not necessary that two or more substance present in a heterogeneous mixture should be of same phase.
Also, it is not necessary that combination of a liquid and a solid always results in a heterogeneous mixture.
If the solid is able to dissolve completely into the liquid then it will result in a homogeneous mixture.
- Whereas a homogeneous mixture is defined as the mixture which contains uniform distribution of solute particles into the solvent.
For example, salt dissolved in water is a homogeneous mixture.
Thus, we can conclude that the statement composition is uniform throughout a homogeneous mixture, is correct.
Angle of Solar Radiation and Temperature
Answer:
According to me end point is the end of a reaction
<u>Answer:</u> The average atomic mass of X is 28.09 amu
<u>Explanation:</u>
Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.
Formula used to calculate average atomic mass follows:
.....(1)
Mass of isotope 1 = 27.979 amu
Percentage abundance of isotope 1 = 92.21 %
Fractional abundance of isotope 1 = 0.9212
Mass of isotope 2 = 28.976 amu
Percentage abundance of isotope 2 = 4.70 %
Fractional abundance of isotope 2 = 0.0470
Mass of isotope 3 = 29.974 amu
Percentage abundance of isotope 3 = 3.09 %
Fractional abundance of isotope 3 = 0.0309
Putting values in equation 1, we get:
Hence, the average atomic mass of X is 28.09 amu
Answer:
B) All carbon atoms have 6 neutrons.
Explanation:
The false statement from the given choices is that all carbon atoms have 6 neutrons.
There is a phenomenon called isotopy in chemistry.
Isotopy is the existence of two or more atoms of the same element having the same atomic number but different mass numbers due to the differences in the number of neutrons in their various nuclei.
- These atoms of elements are called isotopes.
- Carbon atoms generally have proton number of 6 which is the same as the atomic number.
- As with all atoms, the mass number or atomic mass equals the number of protons and neutrons.
For the isotopes of carbon, their number of neutrons differs.
For example:
<em>¹²₆C ¹³₆C ¹⁴₆C</em>
The number of neutrons differs in the above isotopes.
Number of neutrons = mass number - atomic number;
¹²₆C , number of neutrons = 12 - 6 = 6
¹³₆C, number of neutrons = 13 - 6 = 7
¹⁴₆C, number of neutrons = 14 - 6 = 8
Therefore, based on the concept of isotopy, all carbon atoms do not have 6 neutrons.