Question

Question no 25 and 26 guys.would be really helpful if u answer .Thanks:)

Answer 1

25)

a) As three electrons are added to the phosphorus atom & hence is becomes an anion.

So, the Valence shell will have now 5+3 e = 8 electrons

Thu, the new electronic configuration is 2,8,8 which is the electronic configuration of argon and also, p 3- is an stable anion.

b) Isotopes differ in number of neutron but the number of electrons and protons are equal in isotopes. Hence,the physical properties and chemical properties are quite similar of isotopes because of same numbers of protons and electrons present in the isotopes of same atom.

c)

(I) CO-60 is used for treatment of cancer.

(II) Na-24 is used in physical science and engineering as it can produce gamma and beta rays.

(III) Ur-235 is naturally occurring isotope used in nuclear plants and nuclear weapons.

26)

a) we know that 6.022 X 10^23 oxygen atoms constitue to form 1 mol of oxygen

so, 2.58 X 10^24 atoms will constitute to form

=> 2.58 X 10^24/6.022 X 10^23 mol

=> 4.28 mol ( approx )

b) Molecular mass of aluminium oxide = (27 X 2) + (16 X 3 ) g = 102 g

102 g of aluminium oxide will contain 6.022 X 10^23 molecule of aluminium oxide

so, 0.051 g will contain

=> 6.022 X 10^23 X 0.051/102 molecules of aluminium oxide

=> 3.011 X 10^20 molecules of aluminium oxide.

Now, see aluminium ions in a molecule of aluminium oxide is 2 as it's Al 2 O 3

So, the no. of aluminium ions in 0.051 g of aluminium oxide will be

=> 2 X 3.011 X 10^20 ions

=>6.022 X 10^20 ions

I hope You liked the answer

I hope You liked the answerIf it helps Mark it as brainliest answer As I have spend time in answering it in a easy way!

I hope You liked the answerIf it helps Mark it as brainliest answer As I have spend time in answering it in a easy way!#BAL #ANSWERWITHQUALITY

Extra Tip: Watch physics wallah's video on mole concept You will have surely no doubts after that