Sodium (Na) is very reactive because it does not have a full valence shell.
Answer:
Energy lost due to friction is 22 J
Explanation:
Mass of the ball m = 4 kg
Initially velocity of ball v = 6 m/sec
So kinetic energy of the ball 

Now due to friction velocity decreases to 5 m/sec
Kinetic energy become

Therefore energy lost due to friction = 72 -50 = 22 J
the height of the building is H=36 m.
<h3>What is The Law of Gravity?</h3>
According to Newton's law of gravity, every particle of matter in the universe is attracted to every other particle with a force that varies directly as the product of their masses and inversely as their distance from one another.
Properties of Gravity -
- It is a universal attractive force. It is directly proportional to the product of the masses of the two bodies.
- It obey inverse square law.
- It is the weakest force known in nature.
Examples of Gravity -
- The force that holds the gases in the sun.
- The force that causes a ball you throw in the air to come down again.
- The force that causes a car to coast downhill even when you aren't stepping on the gas.
v₀=0 m/s
H₀=0 m
g=10 m/s²
t=7,2 s
H - ?

H = 0 +0 × 7.2 + 10(7.2)²/2
H = 36m
to learn more about Gravity go to - brainly.com/question/12528243
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