Answer:
Positive acceleration involves speeding up, while negative acceleration involves slowing down.
Explanation:
I am so sorry if I was wrong!
22-yes, they belong to the same group
23- they are metals
24-Atoms of group 1 elements all have one electron in their outer shell. This means Na and K have the same valence electrons.
25-Metals are solids at room temperature, therefore Na and K are solid.
26- mass number=A=235
Protons=z=92
Neutrons=mass number-protons
Neutrons=A-Z
Neutrons=235-92
Neutrons=143
Answer : The heat of reaction for the process is, 1374.7 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 main chemical reaction is,

The intermediate balanced chemical reaction will be,
(1)

(2)

(3)

We reversing reaction 1, 3 and multiplying reaction 2 by 2 and then adding all the equations, we get :
(1)

(2)

(3)

The expression for heat of reaction for the process is:



Therefore, the heat of reaction for the process is, 1374.7 kJ
Answer:
it is organism the third one