How many space lattices are obtainable from the different crystal systems?

For which of the following substances are the axial distances equal?

Which of the following is correct regarding crystal systems?

Heat treatment alters the properties of steel due to:

Select the correct option using $T$ (True) or $F$ (False) for the following statements regarding crystal systems:
$(1)$ Crystal system: Cubic,Axial distance: $a = b = c$,Axial angle: $\alpha = \beta = \gamma = 90^{\circ}$,Example: $Cu, KCl$
$(2)$ Crystal system: Monoclinic,Axial distance: $a \neq b \neq c$,Axial angle: $\alpha = \gamma = 90^{\circ}, \beta \neq 90^{\circ}$,Example: $PbCrO_4$
$(3)$ Crystal system: Trigonal (Rhombohedral),Axial distance: $a = b = c$,Axial angle: $\alpha = \beta = \gamma \neq 90^{\circ}$,Example: $CaCO_3, HgS$
$(4)$ Crystal system: Triclinic,Axial distance: $a \neq b \neq c$,Axial angle: $\alpha \neq \beta \neq \gamma \neq 90^{\circ}$,Example: $K_2Cr_2O_7, CuSO_4 \cdot 5H_2O$

Chromium metal crystallises in a body-centred cubic $(bcc)$ lattice. The edge length of the unit cell is found to be $287 \, pm$. The atomic radius of chromium will be ............. $pm$.