Which of the following pairs represent isotopes? A) 28Si and 28S14+
B) 28Si and 28A1
C) 28Si and 29Si
D) 28Si and 28Si4-
E) 28 Si4+ and 28 A13+
O
O
31

C

Explanation:

Isotopes are versions of the same element but with a different number of neutrons.

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.

> b takes place in the gas phase in an isothermal tubular reactor. the feed is one mole of a per one mole of c, an inert. the entering temperature and pressure are 427°c and 10 atm, respectively. the gas constant r = 0.08206 atm · l/mol · k.