Isotopes are atoms of the same element that differ in the number of neutrons.
Remember that all the atoms of an element have the same number of protons. So the only difference between isotopes of an element is the number of neutrons.
86 Sr means that the mass number of this isotope is 86. Also, remember that the mass number is the number of protons plus the number of neutrons.
87 Sr means that the mass number of this isotope is 87.
So, 86 Sr and 87 Sr differ 1 neutron.
Answer: 1 neutron
is the Lewis base in the following reaction:
→ 
<h3>What is lewis base? </h3>
Lewis base is a species that donates an electron pair.
In the above-given chemical equation, the is the lewis base which is donating an electron pair to the central atom of 
to form 
.
Hence, is the Lewis base in the following reaction:
→
Learn more about the lewis base here:
brainly.com/question/15570523
#SPJ1
Answer:
Heat and mass transfer of a LiBr/water absorption heat pump system (AHP) was experimentally studied during working a heating-up mode. The examination was performed for a single spiral tube, which was simulated for heat transfer tubes in an absorber. The inside and outside of the tube were subjected to a film flow of the absorption liquid and exposed to the atmosphere, respectively. The maximum temperature of the absorption liquid was observed not at the entrance but in the region a little downward from the entrance in the tube. The steam absorption rate and/or heat generation rate in the liquid film are not constant along the tube. Hence the average convective heat transfer coefficient between the liquid film flowing down and the inside wall of the tube was determined based on a logarithmic mean temperature difference between the tube surface temperature and the film temperature at the maximum temperature location and the bottom. The film heat and mass transfer coefficients rose with increasing Reynolds number of the liquid film stream.
Answer:
The invention of the wheel had an important impact on farming.
