The correct answer is the last one:
A and C are different elements, while D is an isotope of C.
In fact, A and C are different elements, because they have a different number of protons in the nucleus (A has 3 protons, while C has 4 protons). Instead, D and C are the same element (they both have 4 protons in the nucleus), but they are different isotopes since they have a different number of neutrons (D has 4 neutrons while C has 3 neutrons)
Answer:
B. 450 feet
Explanation:
Due to the angle at which high beam headlights illuminate, they can illuminate the road for about 450 feet.
Answer:
Part a)

Part b)

Part c)

Explanation:
Part a)
As we know that the speed of light is given as


now the frequency of the light is given as

so we have


Part b)
Position of Nth maximum intensity on the screen is given as

so here we know for 3rd order maximum intensity

n = 3
L = 1.4 m


Part c)
angle of third order maximum is given as



Answer:
All statement are correct.
Explanation:
1. Electric field lines are the same thing as electric field vectors, electric field are mathematically vectors quantity. These vectors point in the direction in which a positive test charge would move.
2. Electric field line drawings allow you to determine the approximate direction of the electric field at a point in space. Yes it is correct tangent drawn at any point on these lines gives the direction of electric filed at that point.
3. The number of electric field lines that start or end at a charged particle is proportional to the magnitude of charge on the particle, is a correct statement.
4.The electric field is strongest where the electric field lines are close together, again a correct statement as relative closeness of field lines indicate a stronger strength of electric field.
Hence we can say that all the statement are correct.
Answer:
meters per second squared
Explanation:
Because acceleration is equal to velocity over time where velocity is meters per second and time is measured in seconds making acceleration ms-2