Answer:

Explanation:
You calculate the energy required to break all the bonds in the reactants.
Then you subtract the energy needed to break all the bonds in the products.
2H₂ + O₂ ⟶ 2H-O-H
Bonds: 2H-H 1O=O 4H-O
D/kJ·mol⁻¹: 436 498 464

Answer:
A. displacement) الازاحة
B. المسافة الفعلية للسيارة distance
You will calculate speed from graph (B) because it's the real distance, but (a) is Unreal distance
(II) speed equal distance / time
Speed =(250*1000/5*60*60).
=13.9888888m/s
It is impossible to run 15 miles an hour
I think
Hope this helps :D
The experiment is related to the demonstration using Pepper. When pepper is spread over water, it clumps together This is because pepper is hydrophobic. When repeated with sugar and salt, they instantly dissolved. This means they are attracted to water. When also sprinkled on the surface of the water, it floats. This is caused by surface tension.
To break the surface tension of water, one can use aeration or the use of chemicals such as soap molecules which contain a long chain of hydrogen as well as carbon atoms.
<h3>What is surface tension?</h3>
Surface tension is the propensity of liquid surfaces at rest to shrink to the smallest feasible surface area. Surface tension permits items with a higher density than water, such as razor blades and insects (such as water striders), to float on the water's surface without being immersed.
A force tensiometer can be used to measure surface tension. The forces exerted on a probe situated at the liquid-gas or liquid-liquid interface are measured by these devices.
Learn more about Surface Tension:
brainly.com/question/11348644?
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Answer:
All elements in the same A group will have the same number of
valence electrons.
Explanation:
Group A has 1 valence electrons.