Answer : The amount of heat evolved by a reaction is, 4.81 kJ
Explanation :
Heat released by the reaction = Heat absorbed by the calorimeter + Heat absorbed by the water
![q=[q_1+q_2]](https://tex.z-dn.net/?f=q%3D%5Bq_1%2Bq_2%5D)
![q=[c_1\times \Delta T+m_2\times c_2\times \Delta T]](https://tex.z-dn.net/?f=q%3D%5Bc_1%5Ctimes%20%5CDelta%20T%2Bm_2%5Ctimes%20c_2%5Ctimes%20%5CDelta%20T%5D)
where,
q = heat released by the reaction
= heat absorbed by the calorimeter
= heat absorbed by the water
= specific heat of calorimeter = 
= specific heat of water = 
= mass of water = 254 g
= change in temperature = 
Now put all the given values in the above formula, we get:
![q=[(783J/^oC\times -2.28^oC)+(254g\times 4.184J/g^oC\times -2.28^oC)]](https://tex.z-dn.net/?f=q%3D%5B%28783J%2F%5EoC%5Ctimes%20-2.28%5EoC%29%2B%28254g%5Ctimes%204.184J%2Fg%5EoC%5Ctimes%20-2.28%5EoC%29%5D)
Therefore, the amount of heat evolved by a reaction is, 4.81 kJ
Beryllium, Magnesium, Calcium....etc have two valence electrons
I believe that the answer is 1.8^24 of Ni atoms in 3.6 mol of Ni.
Hope this helps. :)
In a solid the particles are all really close together and stuck like that. As the solid melts and becomes a liquid the particles spread out. A solid won’t easily change its shape because the particles are bound together but in a liquid the shape is more fluid, take water when you pour it into a container it will change to fit the shape of a container this is because the particles aren’t as close and can move around. The particles of a solid change when it melts because it is changing states to a liquid.
At room temperature, water is liquid in form. For helium, it is gas because it is the second lightest element in nature. So, you would expect the density of Helium to be much less than 1 g/cm³. Because gas is very light and occupies a lot of space, the density would result to a very small number.
