Find (a) the total number and (b) the total mass of neutrons in 7 mg of 14C. (Assume that mass of a neutron = 1.675 × 10^–27 kg).
Answers
Answer:
Mass of one neutron
= 1.675 × 10^–27 kg
1 mole of Carbon atom
= 6.023×10²³ atoms
Number of neutrons in 1 carbon atom
= 14-6= 8
So total number of neutrons in 14g of Carbon
= 6.023×10²³×8 neutrons
So 7mg of Carbon will contain
= 6.023 x 10²³ x 8 x 7 x 10^-3 / 14
= [3.37288×10²²]/14
= 2.4092×10²¹ neutrons
So, Mass of 2.4092×1021 neutrons
= [2.4092×10²¹] × [1.675 × 10^–24]
= 4.035×10^–3 g
So, in 7 mg of carbon total number of neutrons is 2.41×10²¹ and the total mass of the neutrons is 4.035× 10^–3 g
number of electrons in 14c=6
therefore number of protons=14-6=8
now....
we know ....1g=1000mg
now mass of 14C= 14g=14×1000mg
will have =(8×6.023×10²³ )numbers of neutrons
therefore ....
in 7mg... number of neutrons is ....
=
mass of a single neutron is =1.675×10^-27kg
therefore mass of 2.4092×10^21 number of neutrons is