Answer:
1. bending of light in gravitational fields.
2. effect of gravitational redshift.
3. perihelion precission of mecury.
Explanation:
1 bending of light in gravitational fields, we can think of it like this:
by noting the change in position s of stars as they pass near the sun on the celetial sphere, so since the sun creates a gravitational field even the star thats not in our line of side(behind the sun) can be seen because its light is bent.
2. effects of gravitational redshift:
this says that if you are in the gravitational field, your clock moves slower when it is seen by a distant observer.
3. perihelion precission of mecury:
according to Newtonian physics a two body system consisting of a lone orbiting the spherical mass would trace out an ellipse with the center of mass of the system as the focus but mercury deviates from that precission. then according to Einstein, the change in orientation of the orbital ellipsewithin its orbital plane is the effect of gravitation being mediated by the curvature of space-time.
Answer: D. The elements have the same number of valence electrons
Explanation: The chemical reactivity of elements is governed by the valence electrons present in the element.
The elements present in the same group or vertical column have similar valence configurations and thus behave similarly in chemical reactions or have similar bonding properties.
For Example: Both fluorine and chlorine belong to same family or group and both have 7 electrons in their valence shell and thus accept single electron to attain noble gas configuration.




thus both would bond with a cation bearing a single positive charge.
Answer:
Part A:

Part B:
Option B (Towards the South)
Explanation:
Part A:
Magnitude if electric field E:
E=Force/charge
Force=2.04×10−14 N
Charge=1.6×10−19 C

Part B:
Option B (Towards the South)
As electron is experiencing the force towards south,it means the direction of the electric field is towards the south because direction of field lines is from positive to negative, so proton is moving towards south it means negative charge is in south to which proton is attracted. So electric field is towards South.
Answer:
a) La aceleración angular es: 
b) El engranaje gira 125 radianes.
c) El engranaje hara aproximadamente 20 revoluciones.
Explanation:
a)
La aceleración angular se define como:

Donde:
- Δω es la diferencia de velocidad angular (en otras palabras ω(final)-ω(inicial))
- Δt es el tiempo en el que occure el cambio de velocidad angular


b)
El desplazamiento angular puede ser calculado usando la siguiente ecuación:

Aqui el angulo inicial es 0, por lo tanto.


El engranaje gira 125 radianes.
c)
Lo que debemos hacer aquí es convertir radianes a revoluciones.
Recordemos que 2π rad = 1 rev
Entonces:

Por lo tanto el engranaje hara aproximadamente 20 revoluciones.
Espero te haya sido de ayuda!