Question

In the table given below, dimensions and angles of various crystals are given. Complete the table by filling the blanks.

	Types of crystal	Dimensions	Angles
1	Cubic	$a=b=c$	$\alpha =\beta =\gamma =$____(P)
2	Tetragonal	______(q)	$\alpha =\beta =\gamma ={90}^o$
3	Orthorhombic	$a \neq b \neq c	______(r)
4	Hexagonal	______(s)	$\alpha =\beta ={90}^o,\gamma =$______(t)

• A. $\left(p\right){90}^o,\left(q\right)a=b\ne c,\left(r\right)\alpha =\beta =\gamma ={90}^o,\left(s\right)a=b\ne c,\left(t\right)-{120}^o$
• B. $\left(p\right){120}^o,\left(q\right)a=b=c,\left(r\right)\alpha ={90}^o,\beta =\gamma ={120}^0,\left(s\right)a\ne b\ne c,\left(t\right){90}^o$
• C. $\left(p\right){90}^o,\left(q\right)a\ne b=c,\left(r\right)\alpha =\beta =\gamma ={120}^o,\left(s\right)a\ne b\ne c,\left(t\right){90}^o$
• D. $\left(p\right){120}^o,\left(q\right)a\ne b\ne c,\left(r\right)\alpha \ne \beta \ne \gamma \ne {90}^o,\left(s\right)a\ne b=c,\left(t\right){120}^o$

Answer 1

The correct option is A $\left(p\right){90}^o,\left(q\right)a=b\ne c,\left(r\right)\alpha =\beta =\gamma ={90}^o,\left(s\right)a=b\ne c,\left(t\right)-{120}^o$

For, cubic crystal, $a=b=c\&\alpha =\beta =\gamma ={90}^o$. So, P is ${90}^o$.

For tetragonal crystal, $a=b\ne c\&\alpha =\beta =\gamma ={90}^o$. So, q is $a=b\ne c$.

For orthorhombic crystal, $a=b=c\&\alpha =\beta =\gamma ={90}^o$. so, r is $\alpha =\beta =\gamma ={90}^o$.

For Hexagonal crystal, $a=b\ne c\&\alpha =\beta ={90}^o\&\gamma ={120}^o$. So, s is $a=b\ne c$ and t is ${120}^o$.