Elements with 7 valence electrons are extremely reactive, while elements with 8 valence electrons practically don't react at all.
This is caused by the fact that all molecules want to have 8 valence electrons; that's just the scientific fact. So, if an element already has 8 valence electrons, it doesn't need to react with anything. If the element only has 7 valence electrons, however, it really wants to react with something with 1 valence electron to get to that special number 8.
Answer:
1.6s
Explanation:
Given that A 1.20 kg solid ball of radius 40 cm rolls down a 5.20 m long incline of 25 degrees. Ignoring any loss due to friction,
To know how fast the ball will roll when it reaches the bottom of the incline, we need to calculate the acceleration at which it is rolling.
Since the frictional force is negligible, at the top of the incline plane, the potential energy = mgh
Where h = 5.2sin25
h = 2.2 m
P.E = 1.2 × 9.8 × 2.2
P.E = 25.84 j
At the bottom, K.E = P.E
1/2mv^2 = 25.84
Substitutes mass into the formula
1.2 × V^2 = 51.69
V^2 = 51.69/1.2
V^2 = 43.07
V = 6.56 m/s
Using the third equation of motion
V^2 = U^2 + 2as
Since the object started from rest,
U = 0
6.56^2 = 2 × a × 5.2
43.07 = 10.4a
a = 43.07/10.4
a = 4.14 m/s^2
Using the first equation of motion,
V = U + at
Where U = 0
6.56 = 4.14t
t = 6.56/4.14
t = 1.58s
Therefore, the time the ball rolls when it reaches the bottom of the incline is approximately 1.6s
I would say C. if im wrong, im sorry. but if im right your welcome. i didnt guess tho.
We are to solve for the net electric field (E) given that there were two electrical charges at point A and B. The given values are the following:
Ea (at point A) = 7.1 x 10^5 newtons/coulomb
Eb (at point B) =2.2 x 10^5 newtons/coulomb
Solving for the net charge, we have:
E = Ea + Eb
E = 7.1x10^5 + 2.2 x10^5
E = 9.3 x 10^5 Newtons/Coulomb
The net electric field is 9.3 x10^5 Newtons/Coulombs.