<u>Answer:</u> The correct answer is Option d.
<u>Explanation:</u>
We are given:
Mass percentage of
= 20 %
So, mole fraction of
= 0.2
Mass percentage of
= 30 %
So, mole fraction of
= 0.3
Mass percentage of
= 35 %
So, mole fraction of
= 0.35
Mass percentage of
= 15 %
So, mole fraction of
= 0.15
We know that:
Molar mass of
= 16 g/mol
Molar mass of
= 28 g/mol
Molar mass of
= 26 g/mol
Molar mass of
= 48 g/mol
To calculate the average molecular mass of the mixture, we use the equation:

where,
= mole fractions of i-th species
= molar masses of i-th species
= number of observations
Putting values in above equation:


Hence, the correct answer is Option d.
Well, when an atom attains a stable valence electron, it means that the outer electrons are complete and so cannot attain any more electrons. For the first shell, it is complete when it has 2 electrons, the second shell is complete when it has 8 electrons, all the other shells also have a particular number when complete. Anyway, i believe the answer is HYDROGEN because when HYDROGEN combines with another atom of HYDROGEN, the outer shell is completed. This is because HYDROGEN has only 1 electron. If the two HYDROGENS, which both have 1 electron combine, they make the electrons 2, which is complete for the first shell, HYDROGEN ends in the first shell. Since the electrons become 2, the shell is at stable valence. In all the other options, this happens;
NEON- It has 10 electrons, 2 in the first shell and 8 in the second. So the the shells are already complete, so it can't bond with any thing, which is completely against the question.
RADON- Radon has 86 electrons.
HELIUM- Helium has 2 electrons, so the shell is already full, and cannot bond, so it goes against the question. The question says BY BONDING.
So the answer is definitely 4) HYDROGEN
Hope i helped. Have a nice day, by the way, i'm very sure it's hydrogen.
Explanation:
Atomic numbers for neutral atoms are the same as the number of electrons. The number of electrons are used in writing the subshell notation where we can see the highest princpal quantum number(n).
In order to solve this problem, a good knowledge of the periodic table and shell notation is required.
For example;
Given a number 5;
We know the number is made of both the atomic number of the element and the highest quantum number.
It is easier for us to know the highest quantum number from the shell notation:
shell notation 1s²2s²2p¹
highest principal quantum number is 2
We are left with atomic number 5-2, which is 3
The element is therefore Li.
Part A. 5, 30, 58, 56, 99, 79, 19, 98, 9
Li Fe I Sb U Ta S Pa N
Part B. 9, 99, 30, 95, 19, 47, 79
N U Fe Ra S Mo Ta
Learn more:
s-orbital brainly.com/question/9288609
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