The first law of thermodynamics characterises the two types of energy transfer, as heat and as thermodynamic. The final internal (thermal) energy of the system is 1,500 J.
<h3>What is internal energy?</h3>
The energy present in a system itself for conducting reactions is called internal energy.
Given,
- Heat entering system (Q) = 700 J
- Work done by the piston (W) = 400
- Initial energy
= 1200 J
According to the <u>first law of thermodynamics</u>:

Substituting values in the above equation:

Therefore, option D. 1500 J is the final energy.
Learn more about internal energy here:
brainly.com/question/2602565
The number of protons and neutrons combined in an atom is called the mass number.
A valid Lewis structure of IF3 cannot be drawn without violating the octet rule.
Answer: IF3 (Iodine Trifluoride)
This is because, I (Iodine) and F (Fluorine) both have odd number of valence electrons (7) which also means that there are too many valence electrons in the valence shell.
If you want an example then a car passing by a standing man is the best one !!
Answer:
C) 0.121 M
Explanation:
HCl + H₂O = H₃O⁺ + OH⁻
.121M .121M
HCl is a strong acid . It will dissociate almost 100 % so the concentration of acid and hydronium ion formed will be equal . It is to be noted that hydronium ion is formed due to association of H⁺ and H₂O . H⁺ is formed due to ionisation of HCl .
So concentrtion of hydronium ion ( H₃O⁺ ) will be .121 M.