<span>The chemical formula of Helium is He.
Question 1 :
Given n = 1.11 x 10^-6
To get no. of the particle,
No of particle = no. of mole x Avogadro Constant
p = n x NA
1 mol of Helium = 6.02 x 10^23
No of atoms = (6.02 x 10^23) x (1.11 x 10^-6)
= 6.66 x 10^17
................................
Question 2 :
Given p = 4.29x10^21
p = n x NA
4.29 x 10^21 = n x (6.02 x 10^23)
(4.29 x 10^21) / (6.02 x 10^23) = n
n = Approximately 7.126 x 10^-3
Hope the answer is right :)</span>
the summer solstice should be your answer
Answer:
Explanation:
The octet rule does not always refer to a stable arrangement of eight valence electrons because there are some element that do not have eight valence electrons yet they are stable. for example;
i) Helium, It has two valence electrons and it is a stable gas.
ii) Boron triflouride (BF3); it has six valence electrons (deficit valence electron) yet it is also stable.
iii) Phosphorus pentachloride (PCl5); it has more than eight valence electron and it is also stable.
For these few reasons it is not always advisable to say octet arrangement refer to stable eight valence electrons.
Answer:
b-acting as a standard unit of measure
Explanation: