C₃H₈ + 5O₂ = 3 CO₂ + 4 H₂O
44.1 g ----------- 4* 18.02 g
? g --------------- 75 g
mass of C₃H₈ = 75 * 44.1 / 4 * 18.02
mass of C₃H₈ = 3307.5 / 72.08
= 45.886 g of propane
3.0 x 10^22
6.0 x 10^23
3.0 x 10^24
Answer: Option (b) is the correct answer.
Explanation:
According to the mole concept there are atoms present in 1 mole of a substance.
Mathematically, 1 mole = atoms or molecules
Therefore, number of atoms present in 0.05 moles of xenon are as follows.
= atoms
or, = atoms
Thus, we can conclude that there are atoms present in 0.05 moles of xenon gas at STP.
(2) a beta particle (4) a gamma ray
Question
Answer:
The answer is D
Like all other krypton atoms, krypton-85 has a unique structure determined by its atomic number and mass number.
Krypton's atomic number is 36, which indicates that it has 36 protons in its nucleus. Krypton-85 is a radioactive isotope of krypton and has 85 nucleons (protons and neutrons) in its nucleus. Its mass number is 85.
An atom of krypton-85 has the following electrical structure:
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶
The krypton-85 atom has 36 electrons spread over various electron shells and orbitals in this electron configuration.
Learn more about krypton-85, here:
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B) an atom with 6 protons and 6 neutrons - an atom with 6 protons and 7 neutrons
C) an atom with 8 protons and 8 neutrons - an atom with 7 protons and 8 neutrons
D) an atom with 7 protons and 6 neutrons - an atom with 6 protons and 6 neutrons
Answer: The correct answer is Option B.
Explanation:
Isotope is defined as the chemical specie which belong to the same element but differ in their molecular mass.
The isotopes have same atomic mass but differ in their mass numbers
Atomic number is defined as the number of protons or electrons that are present in a neutral atom.
Atomic number = number of protons = number of electrons
Mass number is defined as the sum of number of protons and neutrons that are present in an atom.
Mass number = Number of protons + Number of neutrons
Thus, isotopes of an element has same number of protons but they differ in the number of neutrons.
For Example: Chlorine has 2 isotopes,
Number of protons = 17
Number of neutrons = 35 - 17 = 18
Number of protons = 17
Number of neutrons = 37 - 17 = 20
Hence, the correct answer is Option B.