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: The correct answer is zero work done.
Explanation:
Work is said to be done when the object moves through a distance when the force is applied to the object.
If the object does not move a distance even the force is exerted on the object then the work done is zero in this case.
Therefore, when the force is exerted even when no work is done then this is called zero work done.
Answer:
a) Bullet will hit
b) Bullets will not hit
Explanation:
Given:
The velocity of the bullet, u = 
in the rest frame of the bullet pursuit car
The velocity of the original frame of reference, v = 
with respect to the pursuit car.
Now, according to the Galileo
the velocity of the bullet in the original frame of reference (u') will be
u' = u - v
on substituting the values we get
u' = 
or
u' = 
or
u' = 
since this velocity ( ) is greater than the ( 
)
hence,
<u>the bullet will hit</u>
Now, according to the Einstein theory
the velocity of the bullet in the original frame of reference (u') will be
on substituting the values we get
or
or
since,
is less than ( ), this means that the bullet will not hit
Answer:
If two or more atoms of the same element combine, they produce a molecule, for example, H2, O2, O3, etc.
If, however, two (or more) atoms of different elements combine, they produce a compound, for example, NO, CO, FeS, NaCl, etc. The compound may be called a molecule if it is made of independent units, such as NO and CO. However, FeS and NaCl are not molecules because there is no independent unit made of one atom of Fe and a single atom of sulfur or a single unit of Na and Cl. These compound are made of a network of large number of ions of Fe^+2 and S^-2 and Na^+1 and Cl^-1 as a ionic crystallines. If you could isolate a single FeS or NaCl (for example in the gaseous state) you could call them also molecules.
Explanation:
Answer:
Increasing the launch height increases the downward distance, giving the horizontal component of the velocity greater time to act upon the projectile and hence increasing the range.
Explanation:
