a. i.
`Z_(eff(X)) = (n_(c))/(8) + ("Alternate" n_(f))/(2) = (8)/(8) + (2)/(2) = 1 + 2 = 2`
`Z_(eff(Y)) = (n_(b))/(1) + ("Alternate" n_(e))/(4) = (1)/(1) + (4)/(4) = 1 + 1 = 2`
`Z_(eff(X + Y)) = 2 + 2 = 4`
(ii) Total number of atoms in a cube
`= 8` (corner) `+ 2` (alternate face centre)
`+ 4` (alternate edge centre ) `+ 1` (body centre )
`= 15` atom/unit cube
(iii) Formula: `Z_(eff(X)) = 2, Z_(eff(Y)) = 2`
`:.` Formula `= X_(2) Y_(2) = 2XY`
b. i. `Z_(eff(X)) = (n_(c))/(8) + ("Alternate" n_(f))/(2) = (8)/(8) + ((2 - 2))/(2)`
`= 1 + 0 = 1`
`Z_(eff(Y)) = (n_(b))/(1) + ("Alternate" n_(e))/(4) = ((1 - 1))/(1) + ((4 - 4))/(4)`
`= 0 + 0 =` zero
`Z_(eff(X + Y)) = 1 + 0 = 1`
(ii) Total numbe of atom in a cube
`= 8` (corner) `+` zero (body centre)
`+` zero (face centre) `+` zero (edge centre)
`= 8` atoms/unit cube
(iii) Formula: `Z_(eff(X)) = 1, Z_(eff(Y)) = ` zero
`:.` Formula `= X`
c. i.
`:. Z_(eff(X)) = (n_(c))/(8) + (n_(f) ("Alternate"))/(2) = (8)/(8) + (2)/(2)`
`= 1 + 1 = 2`
`Z_(eff(Y)) = (n_(b))/(1) + ( n_(e)("Alternate"))/(4) = ((1 - 1))/(1) + ((4 - 4))/(4)`
`= 0 + 0 = 0`
`Z_(eff(X + Y)) = 2 + 0 = 2`
ii. Total number of atoms in a cube
`= 8` (corner) `+ 2` (alternate face centre)
`+` zero (body centre)
`= 10` atoms/unit cube
(iii) Formula: `Z_(eff(X)) = 2, Z_(eff(Y)) =` Zero
Formula `= X_(2)`
d. i.
`:. Z_(efff(X)) = (n_(c))/(8) + ( ("Alternate")n_(f))/(2) = (8)/(8) + ((2-2))/(2)`
`= 1 + 1 = 2`
`Z_(eff(Y)) = (n_(b))/(1) + ( ("Alternate") n_(e))/(4) = ((1 - 1))/(1) + ((4))/(4)`
`= 0 + 1 = 0 `
`Z_(eff(X + Y)) = 2 + 1 = 3`.
ii. Total number of atoms in a cube
`= 8` (corner) `+ 2` (alternate face centre)
`+ 4` (alternate edge centre) `+` zero
(body centre)
`= 14` atoms/unit cube
(iii) Formula: `Z_(eff(X)) = 2, Z_(eff(Y)) = 1`
`:.` Formula `= X_(2) (Y)`
e. i.
`:. Z_(eff(X)) = (n_(c))/(8) + ("Alternate" n_(f))/(2) = (8)/(8) + (2)/(2)`
`= 1 + 1 = 2 `
`Z_(eff(Y)) = (n_(b))/(1) + ("Alternate" n_(e))/(4) = ((1 - 1))/(1) + (4)/(4)`
`= 0 + 1 = 1 `
`Z_(eff(X + Y)) = 1 + 1 = 2`.
ii. Total number of atoms in a cube
`= 8` (corner) `+ 2` (edge centre) `+ 4` zero(body centre)
`+` zero (face centre) `= 12` atoms/unit cube.
(iii) Formula: `Z_(eff(X)) = 1, Z_(eff(Y)) = 1`.
`:.` Formula `= X Y`.
f. i. i.
`:. Z_(efff(X)) = (n_(c))/(8) + ("Alternate" n_(f))/(2) = (8)/(8) + (2)/(2)`
`= 1 + 1 = 2 `
`Z_(eff(Y)) = (n_(b))/(1) + ("Alternate" n_(e))/(4) = ((1 - 1))/(1) + (4)/(4)`
`= 0 + 1 = 1 `
`Z_(eff(X + Y)) = 2 + 1 = 3`.
ii. Total number of atoms in a cube
`= 8` (corner) `+ 2` (face centre)
`+ 4` (body centre) `+` zero (body centre)
`= 14` atoms//unit cube.
iii. Formula: `Z_(eff(X)) = 2, Z_(eff(Y)) = 1`.
`:.` Formula `= X_(2) Y`.