6. A green colouring material was placed at the centre of a circular piece and allowed to dry. Drops of a solvent were added at the centre and eventually circles were produced as shown below.
(a)Name a suitable solvent for this experiment.
(1 mark)

Nitric oxide (no) can be formed from nitrogen, hydrogen and oxygen in two steps. in the first step, nitrogen and hydrogen react to form ammonia: n2(g) + 2 h_2(g) rightarrow 2 nh_3 (g) delta h = -92. kj in the second step, ammonia and oxygen react to form nitric oxide and water: 4 nh_3(g) + 5 o_2(g) rightarrow 4no(g) + 6 h_2o(g) delta h = -905. kj calculate the net change in enthalpy for the formation of one mole of nitric oxide from nitrogen, hydrogen and oxygen from these reactions. round your answer to the nearest .

Layers of rock containing fossils, like the layers illustrated here, are most likely composed of rocks.

Which of the following words describe the reality that the universe looks the same from various perspective