Answer:
Organisms inhabit nearly every environment on Earth, from hot vents deep in the ocean floor to the icy reaches of the Arctic. Each environment offers both resources and constraints that shape the appearance of the species that inhabit it, and the strategies these species use to survive and reproduce. Some of the broadest patterns of environmental difference arise from the way our planet orbits the Sun and the resulting global distribution of sunlight (Chapin et al. 2002).
Explanation:
In the tropics, where solar radiation is plentiful year-round, temperatures are warm, and plants may photosynthesize continuously as long as water and nutrients are available. In polar regions, where solar radiation is seasonally limited, mean temperatures are much lower, and organisms must cope with extended periods when photosynthesis ceases.
Answer: a) 
b) 
c) 
d) 
Explanation:
General representation of an element is given as:_Z^A\textrm{X}
where,
Z represents Atomic number
A represents Mass number
X represents the symbol of an element
Mass number is defined as the sum of number of protons and neutrons that are present in an atom.
Mass number = Number of protons + Number of neutrons
In an atom, when neutrons or protons are lost or gains, it directly affects the mass number of an atom.
Atomic number is defined as the number of protons or number of electrons that are present in an atom.
It is characteristic of a particular element.
Atomic number = Number of electrons = Number of proton
a) Z 74, A 186: 
b) Z 80, A 201: 
c) Z 34, A 76: 
d) Z 94, A 239.: 
Answer & Explanation:
The reason why is because global fossil fuel consumption is on the rise, and new reserves are becoming harder to find. Those that are discovered are significantly smaller than the ones that have been found in the past.
Oil: Consumption (Predictions): Over 11 Billion tonnes Annually. If we carry on as we are, our known oil deposits could run out in just over 53 years.
Gas (Predictions): If we increase gas production to fill the energy gap left by oil, our known gas reserves only give us just 52 years left.
Coal: Although it’s often claimed that we have enough coal to last hundreds of years, this doesn’t take into account the need for increased production if we run out of oil and gas, our known coal deposits could be gone in 150 years.
For example, oil reserves are a good example: 16 of the 20 largest oil fields in the world have reached peak level production – they’re simply too small to keep up with global demand.
During the year of 2015, fossil fuels made up 81.5% of total U.S. energy consumption. The number is most likely increasing every year.
(fyi: the graph provided is showing future energy reserves for coal, gas and oil. approxiamately.)
3Na2O(at) + 2Al(NO3)3(aq) —> 6NaNO3(aq) + Al2O3(s)
This is a double replacement reaction and NaNO3 is aqueous because Na is an alkali metal, plus nitrate is in the solution. Both of these are soluble. Al2O3 is not soluble because it does not contain any element that is soluble and is hence the precipitate.
Hope this helped!