Answer:
Electrostatic repulsion, strong nuclear force
Explanation:
The nucleus consists of protons and neutrons. protons are positively charged while neutrons possess no charge.
Since protons are positively charged, they repel each other strongly (like charges repel). This strong repulsion of like charges makes the nucleus somewhat unstable leading to spontaneous fission of heavy nuclei.
However, an opposing force called nuclear attractive force tends to hold the nucleons together. This attraction occurs when two nucleons are bonded by a particle called a π meson.
Hence, the two forces that act in the nucleus to create a 'nuclear tug-of-war' are electrostatic repulsion and a strong nuclear force.
Answer:
The amount of each element that begins photosynthesis equals the amount of each element that is produced
Explanation:
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, 
Answer:
Silicon atoms have 14 protons.
Silicon atoms will react with other atoms in order to gain stability.
Silicon atoms have 14 electrons.