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:
8239.2g
Explanation:
Given parameters:
Number of atoms in Br = 6.2 x 10²⁵atoms
Unknown:
Mass of Br = ?
Solution:
From mole concepts, we know that:
1 mole of a substance contains 6.02 x 10²³ atoms/mol
Molar mass of Br = 80g/mol
6.2 x 10²⁵atoms x 
x 80 x 
= 8239.2g
Answer:
4
Explanation:
your chosen answer is right as unsaturated mean contains double bond and 1st and 3rd is Wrong as Carbon only can have 4 bonds and 2nd is Wrong as it is saturated.
hope this helps :)
Answer:
4 moles of Na are needed.
Answer : The correct option is, (B) 
Solution :
According to the Graham's law, the rate of effusion of gas is inversely proportional to the square root of the molar mass of gas.
or,
..........(1)
where,
= rate of effusion of unknown gas = 
= rate of effusion of oxygen gas = 
= molar mass of unknown gas = ?
= molar mass of oxygen gas = 32 g/mole
Now put all the given values in the above formula 1, we get:
The unknown gas could be carbon dioxide 
that has approximately 44 g/mole of molar mass.
Thus, the unknown gas could be carbon dioxide
