The people of Finland, who are secluded to some degree from the rest of the world by water, develop certain diseases due to the lack of genetic material from other ethnicities and races.
Physical barriers prevent fish from one stream from mating with fish from another stream, leading to a less varied gene pool among those fish. As time passes, the fish become unable to successfully mate with other groups.
A mountain range prevents two types of goat from mating, causing the gene pool to become less varied.<span>
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Answer: The correct option is 1.
Explanation: Endothermic reactions are the reactions in which heat is provided to break down the reactant molecules.
In option 1:
The stronger intermolecular forces between the particles in solid molecule are broken down to convert into gaseous form. Hence, some energy in the form of heat is provided to move them far apart. Therefore, it is considered as an endothermic reaction.
In option 2, 3 and 4:
All the other processes involves the formation of bonds and thus there is no need to provide any energy.
Answer:
help with problem 4
Explanation:
4. protons are equal to atomic numbers. neutrons are atomic mass minus atomic number. electrons are equal to protons.
5. I don't know, sorry.
Answer:
2.1 kg of water
Explanation:
Step 1: Given data
- Moles of lithium bromide (solute): 4.3 moles
- Molality of the solution (m): 2.05 m (2.05 mol/kg)
- Mass of water (solvent): ?
Step 2: Calculate the mass of water required
Molality is equal to the moles of solute divided by the kilograms of solvent.
m = moles of solute/kilograms of solvent
kilograms of solvent = moles of solute/m
kilograms of solvent = 4.3 mol /(2.05 mol/kg) = 2.1 kg
Explanation:
d. endothermic change as
heat is added to solid ice to change it to liquid water
