Explanation:
The 2019 water crisis in Chennai has made us realize the importance of saving water more than ever. Water, as we all know, is a finite resource without which our planet would be a barren wasteland. Today with our increasing population it would be logical to say that our water consumption has also increased. And with increasing demand and lesser supply, water scarcity arises. Our ancestors who had foreseen the potential dangers of water scarcity had developed methods to conserve water that was suited for the varied terrain of the Tamil-speaking kingdoms.
Traditional Rainwater Conservation methods of Tamil Nadu
Eri
There are no perennial rivers in Tamil Nadu except the Thamirabharani River which flows through Thirunelveli district. And so, several hundred years ago a simple system was devised to utilize the rainwater to the fullest. An Eri or tank system is one of the oldest forms of water conservation systems in India. Many Eris are still in use in Tamil Nadu and play an active role in irrigation. They act as water reservoirs and flood control systems. They prevent soil erosion, recharge groundwater, and prevent wastage of runoff water during heavy rainfall.
Kudimaramathu
Kudimaramathu is one of the old traditional practice of stakeholders participating in the maintenance and management of irrigation systems. During earlier days, citizens of a village used to actively participate in maintaining the water bodies of their village by deepening and widening the lakes and ponds and restoring the water bodies back to their original form. The silt, rich in nutrients, collected in the process would be used by the farmers themselves in their field. A sense of collective ownership ensured the continued survival of the water bodies.
Gravel is a solid, opaque, heterogenous mixture.
Answer:
mass of CO = 210.42 g
mass in three significant figures = 210. g
Explanation:
Given data:
mass of Fe2O3 = 0.400 Kg
mass of CO= ?
Solution:
chemical equation:
Fe2O3 + 3CO → 2Fe + 3CO2
Now we will calculate the molar mass of Fe2O3 and CO.
Molar mass of Fe2O3 = (55.845 × 2) + (16 × 3) = 159.69 g/mol
Molar mass of CO = 12+ 16 = 28 g/mol
now we will convert the kg of Fe2O3 in g.
mass of Fe2O3 = 0.400 kg × 1000 = 400 g
number of moles of Fe2O3 = 400 g/ 159.69 g/mol = 2.505 mol
mass of CO = moles of Fe2O3 × 3( molar mass of CO)
mass of CO = 2.505 mol × 84 g/mol
mass of CO = 210.42 g
mass in three significant figures = 210. g
Answer:
Oxygen comes 8th on the periodic table which is the atomic number.
Explanation:
but Oxygen 13 (Isotopes of Oxygen) is when oxygen has 8 protons and electrons, and 5 neutrons (8+5=13)
Answer:
See explanation
Explanation:
If we look at the electron configuration closely, we will discover that the element must have had a ground state electron configuration of 2,4.
This is because, the innermost shell usually holds two electrons while the outer shells hold eight electrons each. The four electrons must be accommodated in the second shell in the ground state configuration of the compound.
However, when the atom is excited, one electron from this shell may move to the third shell to give the excited state configuration 2-3-1 as shown in the question.
