Classify each change as physical or chemical.

a. Sugar bums when heated in 3 skillet.

b. Sugar dissolves in water.

c. Apl3tinum ring becomes dull because of continued abrasion.

d. A silver surface becomes tarnished 3fter exposure to air for a long period of time.

Solution 48E: Here we have to convert speed of light in vacuum im m/s to miles/h Therefore, the conversion factors required for such unit conversion is given below (i) m to km 1000 m = 1 km 1 km 1 m = 1000m (ii) km to miles 1 mile =1.6093 km 1 miles = 1 miles/1.6093 km (iii) 60 s =1 min 60s/1 min (iv) 60 min = 1 h 60 min/1 h 8 The speed of light in a vacuum is 2.998 * 10 m/s =2.998 * 10 m/s x 1 km x 1 mile x 60s x 60min 1000 m 1.6093 km 1 min 1 h = 6.706 mile/h 8 Thus, The speed of light in a vacuum is 2.998 * 10 m/s is equal to 6.706 miles/h (b) Here, we have to convert the unit ft into m The conversion factors required for convert the ft to m are given below 1.0 ft = 0.0003048 km 0.0003048 km 1 ft 1 km =1 000 m 1000 m/ 1km Therefore,...