Answer : The final temperature of the metal block is, 
Explanation :

As we know that,

.................(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, 
I cant answer that if I cant see it
Answer:
C + O2 → CO2
Explanation:
C + O2 → CO ----------------- (1)
from equ (1) on reactant side, C has 1 mole, O has 2 moles
from equ (1) on product side, C has 1 mole, O has 1 mole
Thus, to balance the equation, O should have 2 moles
C + O2 → CO2
The element has 83 electrons
Answer:

Explanation:
First you should calculate the volume of a big sphere,so:



Then you calculate the volume of a small spehre, so:



Finally you subtract the two quantities:

