Answer is: (4) proton and neutron.
One unified atomic mass unit is approximately the mass of one nucleon (proton or neutron).
The unified atomic mass unit (amu) is a standard unit of atom mass.
One unified atomic mass unit is approximately the mass of one nucleon (1.66·10⁻²⁷ kg).
For example, one carbon atom has mass of 12 amu (unified atomic mass).
The electron has a mass that is approximately 1/1836 that of the proton.
<span>All
the organisms would reduce in their population.
The sun is the source of the <span>energy that goes up
a food chain. This energy is converted to biomass by primary producers through photosynthesis.
Through interactions such as predation, this energy goes up the food chain from
the primary, secondary and tertiary consumers.
Therefore, if the sun stopped shining, there would be no energy for the food
chain.</span></span>
If the SPF rating is 20 then it means it would provide 20 times the protection instead of no sunscreen and 20 times longer someone would take before the person started to burn or in this case 200 minutes.
