10th Class Important Questions – Page 9

Question: Create a table to describe major river system in India with the following items: direction of flow, countries or regions through which they pass through, and relief features of the areas. (Information skills)

Answer:

Question: What are the different inflow and outflow processes in the context of water resource?

Answer: The water budget of a small or large region such as a village or district depends on the inflow and outflow of water in that region.

Inflow:

Inflow = Precipitation + surface flow + ground water flow
Surface flows includes rivers, streams, canals and other flows on the surface
of water bodies. Precipitation include rainflow, snow dew, hail etc. To estimate precipitation of an area, we take an average over many years, since precipitation varies from year to year. Ground water flow is difficult to estimate, but it can be done.

Outflow:

Evapotranspiration: The total amount of water added to the atmosphere from both evoparation and transpiration is called evapotranspiration.
Water flows out: Some amount of water would flow out of the village as surface flows through streams.

Transpiration:

Trees also give off water into the atmosphere through the process of photosynthesis.
Water for agricultural use, domestic purpose and animal use. Water for industrial use. Water flowing out via surface flows and ground water.

Question: Are you familiar with musical notes?
Answer: In the Indian system of music, there are seven musical notes in a scale – sa, re ga, ma, pa, da, ni. In the west, they use the notations – do, re, mi, fa, so, la, ti. Naturally, there must be some repetition on notes. Every eighth note is similar to the first one and it is the first note of the next scale.

Question: Do you know what Mendeleev said about the melting point of eka Al?
Answer: ‘If I hold it in my hand, it will melt’. The melting point of Ga is 30.2°C and our body temperature is 37°C.

Question: How is Mendeleev honoured?
Answer: At the time when Mendeleev introduced his periodic table even electrons were not discovered. Even then the periodic table was able to provide a scientific base for the study of chemistry of elements. In his honour the 101th element was
named Mendelevium.

Question: Do you know how are the names of certain families of periodic table derived?
Answer: Alkali metal family: Aliquili = Plant ashes, Na, K etc.. were obtained from plant ash, Group I A elements are called Alkali metals family.

Chalcogen family: Chalcogenous = Ore product, as the elements in group 16 (VI A) form ores with metals. They are called as chalcogenous family.
Halogen family: Halos = Sea salt, Genus = Produced. As most of the elements in Group 17 (VII A) are obtained from nature as sea salt. They are called as halogen family.

Noble gases: As the elements of group 18 (VIII A) are chemically least active. They are called as noble gases. There outer shell electronic configuration are basis for octet rule.