1.12(a) air – homogenous mixture(b) tomato juice – heterogeneous mixture ( it separates)(c) iodine crystals – pure substance(d) sand – heterogeneous mixture

1.28(a)

1.25 cm

(b) ρ Ti= 4.51g/cm3

(c) ρ Ben=0.8787g/ml

1.32

16.8cmM=2.17Kg

1.40(a) 320.5 – (6104.5/2.3) divide first, sf=2 320.5 – (2700) subtract, sf=2 -2,400

(b) {(283.5x105) – (1.200 x 103)} x 2.854 in brackets least decimals is 1, sf=4 2.835 x 107 x 2.845 sf=4 8.066 x 107

(c) (0.0045 x 20,000.0) + (2813 x 12) sf of the first bracket is 4, the second is 2 90.00 + 34,000 least decimal places has a sf of 2 34,000

(d) 863 x [1255 – (3.45 x 108)] inner bracket sf=3 863 x [1255- 373] neither bracketed number has decimals so sf = 3 (smallest number) 863 x 882 sf=3 761,000

1.44

(a) V light = 2.998 m/s

(b)

(c)

(d)