Answer: They include elements 57-71, or lanthanides, and 89-103, or actinides. ... Inner transition metals have three incomplete outermost electron shells and are all metals.
Explanation:
In train's rest frame, the speed of photon is 
and the proper length of the train is 
. The time taken by the photon to cross the train is 
In ground frame, the speed of the photon is given as follows:
The speed of light or photon remains same in every frame of reference.
Now, the speed of train is very less as compared to the speed of photon so that 
So that, 
The length contraction in the ground frame is given as follows:
Time taken by the photon to travel the length of the train in ground frame is .
ANSWER:
The Moon's gravity is less than Earth's.
STEP-BY-STEP EXPLANATION:
When you jump, you fall back to the ground. Apples or leaves also fall: we are all attracted to the Earth. It is the terrestrial attraction due to the force of gravity.
The force of gravity also exists on the Moon. But since the Moon is smaller than the Earth, the attraction felt on the Moon is smaller than the Earth's attraction.
As the gravity is less, you can do things such as the one shown in the image.
As the force of attraction is less, the weight is less on the Moon, which can cause things that would be impossible on Earth.
Astronomers use the color of stars to determine how hot they are and their brightness to estimate how far away they are. <em>(D)</em>
