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:
6 different frequencies
Explanation:
From energy level 1 to 2 is one frequency, from energy level 1 to 3 is one frequency and From energy level 1 to 4 is one frequency. So, we have a total of 3 frequencies for transition from energy level 1.
From energy level 2 to 3 is one frequency and from energy level 2 to 4 is one frequency. So, we have a total of 2 frequencies for transition from energy level 2.
From energy level 3 to 4 is one frequency.
So we have a total of 3 + 2 + 1 different frequencies = 6 different frequencies.
Note that the reverse process for each step produces the same frequency as the step in consideration.
Answer: 
Explanation:Bond energy of H-H is 436.4 kJ/mole
Bond energy of C-H is 414 kJ/mol
Bond energy of C=C is 620 kJ/mol
Bond energy of C≡C is 835 kJ/mol

= {1B.E(C≡C)+2B.E(C-H) +1B.E(H-H)} - {1B.E(C=C)+4B.E(C-H)}


Answer:
The formula for water is . The oxidation number of hydrogen is +1. Since there are two of them, the hydrogen atoms contribute to a charge of +2. The water molecule is neutral; therefore, the oxygen must have an oxidation number of to balance the charge.