Mechanical, because the other two make no sense and mechanical energy is the combination of kinetic and potential energy, or moving and still respectively.
Answer:
this is answers to the second picture
Explanation:
1- energy
2- structure
3- reaction
4- substance
5- reactants
6- products
7- changed
8- At first there is no reaction because of the protective oxide coating on the aluminum. But soon an exothermic reaction between bromine and aluminum causes brown fumes of bromine to be given off. But as a new substance, aluminum bromide is produced. White smoke is produced.
9- heated to 120 degrees Celsius it melts and first forms a pale-yellow liquid.
In this form the atoms are covalently bonded, and the liquid can flow easily. However, heated up beyond 150 degrees Celsius, the result is a dark red
10- When a chemical change occurs it is more difficult to revert the substance back to its original state. (To be honest I don't know)
The molar mass of carbon is 12, hydrogen is 1, and
nitrogen is 14, hence the ratio are:
C = 38.65 / 12 = 3.22
H = 16.25 / 1 = 16.25
N = 45.09 / 14 = 3.22
Divide the three by the lowest ratio which is 3.22:
C = 3.22 / 3.22 = 1
H = 16.25 / 3.22 = 5
N = 3.22 / 3.22 = 1
So the empirical formula is:
CHN
The density at 1,291 km from the surface of the planet is
[ (1,291 - planet's radius)/(planet's radius) ] ^ some power .