Answer: 20.2
Explanation:
Mass of isotope 1 = 20
% abundance of isotope 1 = 90.5% =
Mass of isotope 2 = 22
% abundance of isotope 2 = 8.0% =
Mass of isotope 3 = 23
% abundance of isotope 3 = 1.5% =
Formula used for average atomic mass of an element :

Therefore, the average atomic mass of the element is 20.2.
The valence electron configuration for antimony (Sb) is:
Sb = 5s²5p³5d⁰
In SbCl₅²⁻, antimony has a -2 charge i.e. it has 2 additional electrons
Sb²⁻ = 5s²5p⁵5d⁰
Following a two electron transition from p→d orbital we have:
Sb²⁻ = 5s²5p³5d²
There is a total of 5 unpaired electrons (3 in the p and 2 in the d) which can form five bonds with the 5 Cl atoms.
Thus the hybridisation of Sb in SbCl₅²⁻ is sp³d²
Explanation:
An electron cloud is the region of space that surrounds the nucleus of an atom under the nucleus of the negatively charged sub-atomic particles.
- An atoms is made up of some particles.
- The proton is positively charged and it is located in the nucleus of an atom.
- The neutrons do not carry any charges and occupies the nucleus with protons.
- Electrons are the negatively charged particles outside the nucleus.
- The electron cloud is portion of an atom with greatest probability of finding an electron.
Learn more:
Electron cloud brainly.com/question/1832385
#learnwithBrainly
Answer:
q = - 2067.2 J of Heat is giving out when 85.0g of lead cools from 200.0 c to 10.0 c.
Explanation:
The Specific Heat capacity of Lead is 0.128 
This means, increase in temperature of 1 gm of lead by
will require 0.128 J of heat.
Formula Used :

q = amount of heat added / removed
m = mass of substance in grams = 85.0 g
c = specific heat of the substance = 0.128
= Change in temperature
= final temperature - Initial temperature
= 10 - 200
= -
put value in formula
q = - 
On calculation,
q = - 2067.2 J
- sign indicates that the heat is released in the process
The answer is going to be d