Answer:
carbon, nitrogen,oxygen,flourine
Answer:
Option B is correct.
4
Explanation:
We know that an atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example, if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.
In given problem we are given with 2 neutrons of helium. We know that the atomic number of He is 2. Thus Mass number of He is,
Number of neutrons + number of proton
2 + 2 = 4
Thus, option B is correct.
The ions of Noble gases, <em>group VIII</em> elements have a full octet configuration on their outermost shell and as such are highly stable.
The periodic table is a systematic arrangement of elements in order of their atomic numbers into a set of 8 columns each called groups and a set of 7 rows each called a period.
Elements are arranged in different groups according to the number of Valence electrons they have.
- For instance, elements in the group I of the periodic table are highly electropositive and as such are highly reactive.
The same is evident in group 7 elements are highly electronegative and have high electron affinity and as such are unstable and reactive.
- However, Noble gases, <em>group VIII</em> elements have a full octet configuration on their outermost shell and as such are highly stable.
Consequently, the <em>Noble gases ion</em> has a stable Valence electron configuration.
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Answer : The mole fraction of NaCl in a mixture is, 0.360
Explanation : Given,
Moles of 
= 7.21 mole
Moles of 
= 9.37 mole
Moles of 
= 3.42 mole
Now we have to calculate the mole fraction of .
Now put all the given values in this formula, we get:
Therefore, the mole fraction of NaCl in a mixture is, 0.360
I believe the answer is Canada!
