A scientist needs to check several parameters before coming
to a conclusion about the amount of water pollution. The scientists needs to
check the amount of dissolved oxygen in the water, temperature of the water,
the clarity of the water, the PH level of the water and also the amount of
bacteria present in the water. There may be other criteria’s, but the mentioned
ones are enough to gauge the amount of pollution in the water. Scientists often
takes fish and aquatic plants from the water to be tested to check the amount
of pollution indirectly affecting these species.
Answer:
4Fe+ 6H2 O+ 3O2 ----> 4Fe(OH)3
Here, Number of atoms = 0.46 * 6.23 * 10^23 [ Avogadro's number ]
= 2.77 * 10^23
In short, Your Answer would be Option B
Hope this helps!
Answer:
The reactivity of Group 7 elements decreases down the group. ... The electrons in the outer shell move further away from the nucleus as we go down the group and the attraction force between the electrons and the nucleus become weaker and weaker. This weaker attraction in the larger atoms makes it harder to gain electron.
