I think it’s I
Iodine has 53 protons and 74 neutrons
Answer:
K
Explanation:
The picture that demonstrates a state of matter without a fixed shape or fixed volume is picture K.
Gases are one of the three states of matter without a fixed shape and volume. They simply take up the shape of their containers and are free to move all about.
- Liquids and solids are known to have fixed shape and volume.
- Liquids are know for their ability to flow. Figure L
- Solids are rigid bodies. It is the figure J
Answer : The enthalpy change of reaction is -1800 kJ
Explanation :
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The given final reaction is,

The intermediate balanced chemical reaction will be,
(1)

(2)

First we will multiply reaction 1 by 2 and reverse reaction of reaction 2 by 3 then adding both the equation, we get :
The expression for final enthalpy is,
![\Delta H=[n\times \Delta H_1]+[n\times (-\Delta H_2)]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5Bn%5Ctimes%20%5CDelta%20H_1%5D%2B%5Bn%5Ctimes%20%28-%5CDelta%20H_2%29%5D)
where,
n = number of moles
![\Delta H=[2mole\times (-1680kJ/mole)]+[3\times -(-520kJ/mole)]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5B2mole%5Ctimes%20%28-1680kJ%2Fmole%29%5D%2B%5B3%5Ctimes%20-%28-520kJ%2Fmole%29%5D)

Therefore, the enthalpy change of reaction is -1800 kJ
Answer:
The average kinetic energy of the molecules in the system
Explanation:
According to the kinetic theory of matter, the particles of a system are in constant motion and collide steadily with one another as well as with the walls of the container.
The average kinetic energy of these molecules in motion is referred to as the temperature of the body. Hence, temperature is a measure of the average kinetic energy of the molecules of a body.
Answer:
When fuels are incompletely burnt, they release carbon monoxide gas into the atmosphere. This gas is very dangerous as it is poisonous in nature
Explanation: