1
JEE Main 2024 (Online) 6th April Morning Shift
MCQ (Single Correct Answer)
+4
-1

Which of the following material is not a semiconductor.

A
Copper oxide
B
Graphite
C
Silicon
D
Germanium
2
JEE Main 2024 (Online) 5th April Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

The correct statements from the following are :

(A) The decreasing order of atomic radii of group 13 elements is $$\mathrm{Tl}>\mathrm{In}>\mathrm{Ga}>\mathrm{Al}>\mathrm{B}$$.

(B) Down the group 13 electronegativity decreases from top to bottom.

(C) $$\mathrm{Al}$$ dissolves in dil. $$\mathrm{HCl}$$ and liberates $$\mathrm{H}_2$$ but conc. $$\mathrm{HNO}_3$$ renders $$\mathrm{Al}$$ passive by forming a protective oxide layer on the surface.

(D) All elements of group 13 exhibits highly stable +1 oxidation state.

(E) Hybridisation of $$\mathrm{Al}$$ in $$[\mathrm{Al}(\mathrm{H}_2 \mathrm{O})_6]^{3+}$$ ion is $$\mathrm{sp}^3 \mathrm{d}^2$$.

Choose the correct answer from the options given below :

A
(A), (B), (C) and (E) only
B
(C) and (E) only
C
(A), (C) and (E) only
D
(A) and (C) only
3
JEE Main 2024 (Online) 5th April Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

The number of neutrons present in the more abundant isotope of boron is '$$x$$'. Amorphous boron upon heating with air forms a product, in which the oxidation state of boron is '$$y$$'. The value of $$x+y$$ is _________ .

A
9
B
6
C
4
D
3
4
JEE Main 2024 (Online) 1st February Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
Given below are two statements :

Statement (I) : $\mathrm{SiO}_2$ and $\mathrm{GeO}_2$ are acidic while $\mathrm{SnO}$ and $\mathrm{PbO}$ are amphoteric in nature.

Statement (II) : Allotropic forms of carbon are due to property of catenation and $\mathrm{p} \pi-\mathrm{d} \pi$ bond formation.

In the light of the above statements, choose the most appropriate answer from the options given below :
A
Statement I is false but Statement II is true
B
Both Statement I and Statement II are false
C
Both Statement I and Statement II are true
D
Statement I is true but Statement II is false
JEE Main Subjects
EXAM MAP
Medical
NEET
Graduate Aptitude Test in Engineering
GATE CSEGATE ECEGATE EEGATE MEGATE CEGATE PIGATE IN
Civil Services
UPSC Civil Service
CBSE
Class 12