Answer : The final temperature of the metal block is, 
Explanation :
As we know that,
![m_1\times c_1\times (T_{final}-T_1)=-[m_2\times c_2\times (T_{final}-T_2)]](https://tex.z-dn.net/?f=m_1%5Ctimes%20c_1%5Ctimes%20%28T_%7Bfinal%7D-T_1%29%3D-%5Bm_2%5Ctimes%20c_2%5Ctimes%20%28T_%7Bfinal%7D-T_2%29%5D)
.................(1)
where,
q = heat absorbed or released
= mass of aluminum = 55 g
= mass of water = 0.48 g
= final temperature = ?
= temperature of aluminum =
= temperature of water =
= specific heat of aluminum = 
= specific heat of water= 
Now put all the given values in equation (1), we get
![55g\times 0.900J/g^oC\times (T_{final}-25)^oC=-[0.48g\times 4.184J/g^oC\times (T_{final}-25)^oC]](https://tex.z-dn.net/?f=55g%5Ctimes%200.900J%2Fg%5EoC%5Ctimes%20%28T_%7Bfinal%7D-25%29%5EoC%3D-%5B0.48g%5Ctimes%204.184J%2Fg%5EoC%5Ctimes%20%28T_%7Bfinal%7D-25%29%5EoC%5D)
Thus, the final temperature of the metal block is,
The Atacama Desert is a plateau in South America.
Covering a 1,000-kilometre strip of land on the Pacific coast.
West of the Andes mountains. It is the driest non-polar desert in the world.
In the late 1800s, Chile and Bolivia disputed this land in the Guerra del Pacífico (War of the Pacific) becaue both countries claimed to be rightful owners of this region that.
During the day, temperatures in the desert can reach around 40º C (104º F).
Answer:
Four electrons are present in the valence shell of Silicon.
Explanation:
Valence shell electrons are those electrons which are present in the outermost shell of an atom. These valence shell electrons are responsible for in the formation of bonds with other atoms.
Silicon having atomic number 14 has fourteen electrons in its neutral state and has the electronic configuration as follow;
1s², 2s², 2p⁶, 3s², 3p²
In given configuration the valence shell (outermost shell) is 3 and the number of electrons present in it are four i.e. 3s² and 3p² (2 + 2 = 4) respectively.
Answer:
C. It blocked out sunlight
Explanation:
The asteroid impact 65 million years ago was devastating for lot of the animals and plants, resulting in a mass extinction, most noticeably of the dinosaurs. The impact itself killed a lot of flora and fauna, but it was the effect afterward that was crucial. From this impact, there was so much debris propelled into the atmosphere that the sunlight got blocked. Once this happened, most of the plants died out as they were not able to perform photosynthesis. Because the plants were dying out, the herbivores were left without food, so soon they followed, and because the herbivores died out, the predators died out to because they were left without food. The winners turned out to be the small and not specialized plants and animals.
Answer: An Element
Explanation:
An element is a substance that cannot be split into smaller substance. It is made up of one kind of atom and can exist either as molecules (e.g nitogen) or an atom (e.g argon).
