The answer is 200 J
The kinetic energy (KE) is:
KE = 1/2 m * v²
m - mass of the object
v - velocity of the object
We have:
m = 4 kg
v = 10 m/s
KE = 1/2 * 4 kg * 10² m/s
KE = 200 J
The reaction involved in present case is:
Net Reaction: Ca + 1/2 O2 → CaO. ..................(1)
In terms of oxidation and reduction, the reaction can be shown at
Oxidation: Ca → Ca2+ + 2e- .................(2)
Reduction: 1/2O2 + 2e- → O2-...................(3)
From, reaction 1 it can be seen that 1 mol of Ca reacts with 1/2 mol of O2 to form 1 mol of CaO.
From, reaction 2 it can be seen that 1 mol of Ca, generates 2 mol of e-.
Thus, when 1/2 mol of Ca is used in reaction, it will lose 1 mol of electrons.
Answer:
C) ball rollinflown a hill
Explanation:
The question asks to identify the endothermic process in the list of options. By way of elimination, we have;
A) condensation of water on a wind shield of a car
Condensation is an exothermic process. That is, heat is given out as the gases change into the liquid state of matter.
B) formation of copper
This is an exothermic process. Capture of electrons by a cation is always exothermic.
C) ball rollinflown a hill
This is the correct option. Energy is absorbed by the ball as it moves on the hill
D) formation of ice from liquid water
Freezing is an example of exothermic reaction. Heat is given off to the surroundings.
E) oxide from copper and oxygen
Formation of metal oxides and most reactions involving oxygen are exothermic reactions,
i think it is 6 valence electrons
