Determine the number of neutrons for the given isotopes. helium-3 carbon-14 nitrogen-15 strontium-90 tellurium-123

Number of neurons in

Helium = 1

Carbon = 8

Nitrogen = 8

Strontium = 52

Tellurium = 71

Explanation: Isotopes are the forms of same element having different mass numbers. They only differ in the number of neutrons. The number of protons remain same. and are the two isotopes of same element X.

Neutrons can be calculated by:

Number of neutrons = Mass Number - Number of neutrons

and Atomic Number = Number of protons

For the given elements, Mass numbers are given

Atomic Number of Helium = 2

Given mass number = 3

Number of neutrons in Helium= (3 - 2) = 1

Similarly,

Number of neutrons in Carbon = (14 - 6) = 8

Number of neutrons in Nitrogen = (15 -7) = 8

Number of neutrons in Strontium = (90 - 38) = 52

Number of neutrons in Tellurium = (123 - 52) = 71

a 20-cm-long, cylindrical graphite (pure carbon) rod is inserted into an oxidizing atmosphere at 1145 k and 1.013 x 105 pa pressure. the oxidizing process is limited by the diffu- sion of oxygen counterflow to the carbon monoxide that is formed on the cylindrical surface.