Scientists have many problems that they are working on but are unable to reach a useful solution. There are a number of constraints that can make problems unable to have a solution. Match the current scientific problem and the major constraint to finding a solution.

well , a current problem as you know is covld 19. scientist struggle to find a cure or solution to this because we don't know enough about it because the disease or illness developed so recently. because we don,t know enough about it, we don't have the needed knowledge to finding a solution. We don,t know the DNA/RNA stands in this virus, we don't know how it spreads so fast, how it can infect animals and humans as we don,t have similar DNA strands except for monkeys but dogs have been infected with the virus. it simply because of the unknown. hope this helps as an example!

the leaf is an organ of a typical plant, and the main functions are to complete photosynthesis and allow the plant to exchange gas, just like how we have the respiratory system. leaves have the stomata, which collects maintains co2 and o2 levels. this is necessary for cell metabolism. the leaf also collects sunlight using chloroplasts. succinctly, leaves own a pivotal role in sustaining plant life.

"standard molar enthalpy:

h2o ( liquid water ) : - 285.8 kj/mole

h2o ( water vapor ) : - 241.8 kj / mole.

δhrxn = - 241. 8 - ( - 285.8 )= -241.8 + 285.8 = 44.0

answer: 44.0 kj"