Cold air is dense and warmer air is less dense and so as the cool dense air sinks the warm air rises and takes its place causing a convection current. This is the same with water and other gaseous and liquid substances.
Answer:
TRUE
Explanation:
The earth is comprised of three distinct layers namely the core, mantle and the crust. The core is the extreme interior layer which is comprised of the denser elements like iron, nickel and other siderophile elements. Thee denser minerals are deposited, by sinking into the core of the earth forming the highest density layer. The core was formed about 1 to 1.5 billion years back.
Whereas, the least dense elements were concentrated in the upper region of the earth forming the crust. These are the lighter elements so it did not get sink into the bottom. But still many of these elements are found in association with the core rocks. There occurred constant evolution on the crustal portion of the earth.
Thus, these elements are found in larger proportions in the crust and were formed during the initial formation of the earth.
Hence, the above-given statement is True.
Answer:
Baikal is also the world's most ancient freshwater lake, it originated 20-25 million years ago. » It is home to many unique species of animals and plants including the freshwater seal. » Lake Baikal is one of the clearest and purest bodies of water. In a good day you could see 40 meters into the lake.
Explanation:
I don't understand stand what you saying
Answer:
Gentrification.
Explanation:
Gentrification is the renewal and rebuilding of the urban environment, which takes place when wealthier middle-class people move to declining areas, displacing the lower-class people there. As a result of gentrification, the average family income in the community increases and the number of members decreases. This is believed to be due to the departure of poorer residents who are unable to pay the increased rent and other real estate and land taxes. Old industrial buildings are often converted into dwellings and shops. In addition, new stores and service facilities are moving to the area, serving a wider customer base. This in turn increases the attractiveness of the region for more affluent immigrants and reduces accessibility for the poorer. This process is often made possible by government-funded investments to improve local infrastructure, mortgages for poor and first-time home buyers, and financial bonuses for owners of dilapidated houses. Following the implementation of these economic measures, crime in the area tends to decrease and real estate prices and tax revenues rise.
