IIT JEE exam which consists of JEE Main and JEE Advanced is one of the most important entrance exams for engineering aspirants. The exam is held for candidates who are aspiring to pursue a career in the field of engineering and technical studies.
Chemistry is important because everything you do is chemistry! Even your body is made of chemicals. Chemical reactions occur when you breathe, eat, or just sit there reading. All matter is made of chemicals, so the importance of chemistry is that it's the study of everything..

**Q1.**The wave mechanical model of an atom is based upon which of the following equations?

Solution

Part D

Part D

**Q2.**The correct set of four quantum numbers for the valence (outermost) electron of rubidium (Z=37) is

Solution

(b)

Rb(z=37)

[Kr]_36 5s^1

For the last electron:

n=5,l=0,m=0,s=1⁄2

(b)

Rb(z=37)

[Kr]_36 5s^1

For the last electron:

n=5,l=0,m=0,s=1⁄2

**Q3.**The radiation that produces the greatest number of ions as it passes through matter is

Solution

Part A

Part A

**Q4.**The decay of a radioactive element follows first order kinetics. Thus,

Solution

(a)

t_(1/2)=0.693/K

(a)

t_(1/2)=0.693/K

**Q5.**After three half lives, the percentage of fraction of amount left is

Solution

(b)

Given n=3, we know that N=(1/2)^n N_0

∴(N/N_0 )=(1/2)^n=1/8 Or N/N_0 %=1/8×100=12.5%

(b)

Given n=3, we know that N=(1/2)^n N_0

∴(N/N_0 )=(1/2)^n=1/8 Or N/N_0 %=1/8×100=12.5%

**Q6.**The SI unit of radioactivity is

Solution

Part A

Part A

**Q7.**Which nuclear reaction is not balanced?

Solution

(b)

_92^238 U+ _2^4 He→ _95^241 Am+ _0^1 n

LHS RHS

Mass number 242 242 balanced

Atomic number 94 95 unbalanced

(b)

_92^238 U+ _2^4 He→ _95^241 Am+ _0^1 n

LHS RHS

Mass number 242 242 balanced

Atomic number 94 95 unbalanced

**Q8.**Atoms with the same mass number but having different nuclear charges are called

Solution

(b)

Isobars have different mass number

(b)

Isobars have different mass number

**Q9.**The number of radial nodes of 3s and 2p-orbitals are respectively

Solution

(a)

Number of radial nodes =(n-l-1)

For 3s,n=3,l=0(number of radial node=2)

For 2p,n=2,l=1(number of radial node=0)

(a)

Number of radial nodes =(n-l-1)

For 3s,n=3,l=0(number of radial node=2)

For 2p,n=2,l=1(number of radial node=0)

**Q10.**C-14 has a life of 5760 years. 100 mg of sample containing C-14 is reduced to 25 mg in

Solution

Part A

Part A