In a forward collision, the driver and everyone else's head is thrusted back (because the energy transfer from one car to another [i.e. the Inertia] ).. the head rest is there to stop the heads from moving to far back that it could break your neck.
Chemical Potential Energy is released when chemical bonds between atoms are broken (like covalent and ionic) and is released mainly as thermal
Elastic Potential is released when the molecules in the material are allowed to go back to there original form, and is released mainly as kinetic
Answer:
0.3 moles of H2 will be produced.
Explanation:
Balanced reaction: 2 Al + 6 HCl → 2 AlCl3 + 3 H2
Given Al mass = 5.4 g, we know Mr of Al is 27
Using the formula:
moles = mass / Mr
moles of Al = 5.4 / 27
moles of Al = 0.2 moles
Here we see that "2" molar mass before Al; so in this reaction, "1" molar mass will have [(0.2)/2] = 0.1 moles. He see "3" molar mass before H2, therefore moles of H2 is (3 * 0.1) = 0.3 moles.
Answer:
C. Hydrogen Ions.
Explanation:
The pH level of soils is measured based upon the acidity or basicity level in the soil. The pH scale usually measures between 0-14. 7 is the neutral pH level of soil and a pH level below 7 is considered acidic and above 7 is alkaline.
So, soil with a high amount of hydrogen ions (H+) will be considered acidic. As the amount of hydrogen ions increases in the soil, the pH level of the soil decreases, making it acidic.
Therefore, option C is correct.